tag:theconversation.com,2011:/us/topics/male-fertility-18198/articlesMale fertility – The Conversation2024-03-06T13:23:22Ztag:theconversation.com,2011:article/2239182024-03-06T13:23:22Z2024-03-06T13:23:22ZBoxers, briefs and bacterial vaginosis: how your underwear can affect your health<figure><img src="https://images.theconversation.com/files/579029/original/file-20240229-22-9jmolr.jpg?ixlib=rb-1.1.0&rect=25%2C8%2C5582%2C3724&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/underwear-colored-funny-panties-256670413">Sylvia Biskupek/Shutterstock</a></span></figcaption></figure><p>Thongs, briefs, long johns, g-string, boxers, trunks: there’s a bewildering array of undies out there. But which ones are best for the health of your nether regions?</p>
<p>Well, the style of underwear you choose is less important than the material it is made of. Natural fibres such as cotton are far better for the skin, especially the sensitive areas around the genitals, where breathability of the garment is important. </p>
<p>But, even if your pants drawer is full of cotton briefs, you’ll still need to be wary of fit, dyes and dirt. Here’s what women and men need to know about the links between their underwear and their health.</p>
<p>For those who have one, it’s important to remember the vagina is a self-cleaning organ. It <a href="https://www.uptodate.com/contents/vaginal-discharge-in-adult-women-beyond-the-basics/print">produces up to 5ml</a> of fluid per day and has a balanced microflora consisting of many different bacteria – although it’s typically dominated by those of the <em>lactobacillus genus</em>. </p>
<p>These <a href="https://www.sciencedirect.com/science/article/pii/S0923250817300839">bacteria produce lactic acid</a> which ensures the vagina maintains the correct, <a href="https://pubmed.ncbi.nlm.nih.gov/15838694/">typically slightly acidic, pH</a>, reducing the risk of infection.</p>
<p>There’s limited research on how underwear style might impact vaginal health. The most <a href="https://journals.lww.com/greenjournal/abstract/2018/05001/brief_vs_thong_hygiene_in_obstetrics_and.375.aspx">notable study</a>, though, found that thong-wearers were more likely to report urinary tract infections (UTIs), vaginal yeast infections and bacterial vaginosis. </p>
<p>However, it may not be the thong itself that causes infection: in the study, UTIs were associated with oral sex and bacterial vaginosis was linked to non-cotton crotch underwear.</p>
<p><a href="https://www.nhs.uk/conditions/bacterial-vaginosis/">Bacterial vaginosis</a> is a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4141851/">dysbiosis</a> – a bacterial imbalance – in the vagina that can be caused by non-breathable underwear. Synthetic fibres, and the dyes used to colour them, can <a href="https://www.ncbi.nlm.nih.gov/books/NBK543220/">alter the conditions</a> of the vagina leading to a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3654610/">sub-optimal conditions</a> for good bacteria (such as <em>lactobacilli</em>) to exist. </p>
<p>Synthetic, dyed underwear can cause pH levels to <a href="https://www.ncbi.nlm.nih.gov/books/NBK2495/">increase to over 4.5</a> allowing anaerobic bacteria to thrive and <a href="https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01936/full"><em>lactobacilli</em> to perish</a>. These conditions can lead to bacterial vaginosis, or an increase in the growth of fungi such as <em>candida albicans</em>, causing thrush.</p>
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<p>However, it seems that wearing tight-fitting clothing, including underwear, over time <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1649629/">may increase candida</a> levels in the groin. </p>
<p>Underwear that is too tight fitting can also cause friction and irritation around the genitals. This can result in anything from <a href="https://www.nhs.uk/conditions/skin-tags/">skin tags</a> (which may look like genital warts depending on their location), ingrown hairs and blisters.</p>
<h2>Forget the budgie-smugglers</h2>
<p>In men, the testes are the primary site of sperm production. They hang away from the body to achieve a 2°C-4°C cooler environment. Testicular temperature is so important that the body has its own means – <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3158898/">the pampiniform plexus</a> – to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3971494/">cool the arterial blood</a> as it flows into the testes. </p>
<p>There is scant research on the exact effect of underwear type on sperm quality and quantity. However, research found that those who reported frequent wearing of boxer shorts had <a href="https://pubmed.ncbi.nlm.nih.gov/30102388/">a higher sperm concentration</a> than those who wore other types of underwear. Boxers, also demonstrated and maintained a reduced scrotal temperature. </p>
<p>There’s also research to show that <a href="https://www.ajog.org/article/0002-9378(65)90080-3/abstract">increased</a> scrotal temperatures in men from a variety of <a href="https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-2605.1997.d01-303.x">contexts and occupations</a>, resulted in <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9588744/">marked reduction</a> in sperm count for weeks. Thankfully, in most settings sperm count is <a href="https://www.scielo.br/j/ibju/a/DZ7qfNnKzYGk6vdMC8HWjRB/?lang=en">recoverable</a>. </p>
<p>The impact across a number of weeks is likely because it takes approximately 74 days for a sperm to be born and reach maturity with ability to exit the body, and temperature can affect sperm at any point in its journey.</p>
<p>However, men who undergo vasectomy are advised to wear <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3444593/">tight fitting underwear for at least 48 hours</a> and up to seven days post-operation. The tight fit helps support the testes, reducing their movement and the strain on the very thin layers of <a href="https://theconversation.com/fascia-the-most-neglected-part-of-our-body-is-finally-starting-to-receive-attention-213511">fascia</a> and muscles that cover the testes. Movement results in pain, as well as a risk of opening any wounds, and increases the chances of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8255399/">infection</a>.</p>
<h2>Keep it clean</h2>
<p>Cleanliness of the body and the underwear is essential for everyone. Research shows that even clean underwear can contain <a href="https://www.journalofinfection.com/article/S0163-4453(01)90852-7/pdf">0.1b-10g of faecal matter</a>, and those bacteria have the potential to make you ill. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/579219/original/file-20240301-16-ccf2gk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/579219/original/file-20240301-16-ccf2gk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/579219/original/file-20240301-16-ccf2gk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/579219/original/file-20240301-16-ccf2gk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/579219/original/file-20240301-16-ccf2gk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/579219/original/file-20240301-16-ccf2gk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/579219/original/file-20240301-16-ccf2gk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Avoid brightly coloured underwear, choose natural fabrics and wash them regularly to keep your genitals happy.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/red-panties-boxer-briefs-underwear-on-552320857">DenisProduction.com/Shutterstock</a></span>
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<p>Cleaning the skin, as well as your underwear, reduces the potential for fungal infections too, such as <a href="https://patient.info/infections/fungal-infections/fungal-groin-infection-tinea-cruris">tinea cruis</a>, sometimes known as jock itch. </p>
<p>This red or brown itchy rash is four times more common in <a href="https://www.sciencedirect.com/science/article/pii/S1555415505003235#bib2">men than women</a>. Athletes typically present with fungal infections in their groin from increased heat and sweat generated while exercising. Sportsmen tend to develop the infection along the crease between the scrotum and thigh because of the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4804599/">tight-fitting underwear</a> worn during contact sports. </p>
<h2>You can go commando – but take care with zips</h2>
<p>Foregoing the barrier underwear creates between sensitive areas can actually be beneficial. Going commando enables air to circulate, allowing secretions to dry naturally, reducing the moist conditions that can contribute to infections.</p>
<p>The main risk of going underwear-free <a href="https://www.ncbi.nlm.nih.gov/books/NBK441886/">seems to be for men who’re careless with trouser fastenings</a>. Injuries from <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3692577/">zip fastenings</a> almost always involve men damaging their penis or scrotum. </p>
<p>So, picking natural, breathable fabrics – and perhaps button-fastenings – are best for health down there. And always remember, if something doesn’t look or smell right it is best to get it checked out.</p><img src="https://counter.theconversation.com/content/223918/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Taylor does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>‘Make sure you always wear clean pants’ isn’t just something your mum used to say – keeping your underwear scrupulously clean could stop you from getting illAdam Taylor, Professor and Director of the Clinical Anatomy Learning Centre, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2177872023-12-11T01:07:04Z2023-12-11T01:07:04ZMale infertility is more common than you may think. Here are 5 ways to protect your sperm<figure><img src="https://images.theconversation.com/files/562602/original/file-20231130-15-oj3ctt.jpg?ixlib=rb-1.1.0&rect=15%2C0%2C5126%2C3592&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Infertility is often thought of as a female problem but <a href="https://theconversation.com/problems-conceiving-are-not-just-about-women-male-infertility-is-behind-1-in-3-ivf-cycles-192183">one in three IVF cycles</a> in Australia involve male infertility.</p>
<p>We recently published a <a href="https://pubmed.ncbi.nlm.nih.gov/37695221/">review of the literature</a> on whether men diagnosed with male factor infertility experience greater psychological distress than fertile men or men with an infertile partner. We found irrespective of the cause of infertility, men in couples with infertility have more symptoms of depression, anxiety and general psychological distress, worse quality of some aspects of life, and lower self-esteem than fertile men. </p>
<p>Research also shows sperm counts are <a href="https://doi.org/10.1093/humupd/dmac035">declining worldwide</a>, and that lifestyle and environmental factors can reduce male fertility.</p>
<p>While most <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7008178/">male causes of infertility</a> are not preventable, it’s important to know how to keep your sperm as healthy as possible. Here are five things men can do to boost their fertility. </p>
<h2>1. Try to be in the healthy weight range</h2>
<p>Obesity <a href="https://doi.org/10.1016/j.fertnstert.2023.10.017">causes hormonal changes</a> that have <a href="https://pubmed.ncbi.nlm.nih.gov/32399992/">negative effects on semen</a>, including the total number of sperm, the ability of the sperm to move, the number of live sperm, and the number of sperm with a normal shape. </p>
<p>These reduce the chance of both <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/andr.13552">spontaneous and IVF conception</a>.</p>
<p>The good news is the adverse effects on fertility caused by excess weight in men are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4408383/">reversible</a>. Regular <a href="https://doi.org/10.1016/j.fertnstert.2023.10.017">exercise</a> and a healthy diet can help reduce weight and improve sperm quality. </p>
<p>There is strong evidence a healthy diet rich in fruits, vegetables, whole grains, nuts, low-fat dairy, and seafood, and low in red and processed meats, sweets, and sweetened beverages is linked to <a href="https://doi.org/10.1016/j.fertnstert.2023.10.013">better sperm quality</a>.</p>
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<strong>
Read more:
<a href="https://theconversation.com/problems-conceiving-are-not-just-about-women-male-infertility-is-behind-1-in-3-ivf-cycles-192183">Problems conceiving are not just about women. Male infertility is behind 1 in 3 IVF cycles</a>
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<h2>2. Avoid recreational drugs</h2>
<p>Recreational drug use is associated with poorer reproductive health. Psychoactive drugs such as cocaine, benzodiazepines, heroin, methamphetamine, oxycodone and ecstasy <a href="https://rbej.biomedcentral.com/articles/10.1186/s12958-023-01098-2">negatively affect male reproductive functions</a> including sexual urge, testosterone production, sperm production and sperm quality. </p>
<p>While research on the link between <a href="https://doi.org/10.1111/andr.12585">marijuana use and sperm quality</a> is inconclusive, some evidence suggests frequent marijuana use can reduce sperm quality and is a risk factor for testicular cancer. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/562606/original/file-20231130-23-6t0is.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Man's hand holding up bag of white powder" src="https://images.theconversation.com/files/562606/original/file-20231130-23-6t0is.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/562606/original/file-20231130-23-6t0is.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/562606/original/file-20231130-23-6t0is.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/562606/original/file-20231130-23-6t0is.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/562606/original/file-20231130-23-6t0is.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/562606/original/file-20231130-23-6t0is.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/562606/original/file-20231130-23-6t0is.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Recreational drug use is associated with poorer reproductive health.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<h2>3. Stay clear of anabolic steroids</h2>
<p>Some men use anabolic steroids to enhance their physical performance and appearance. Globally, it’s estimated about <a href="https://doi.org/10.1016/j.fertnstert.2023.09.016">one in 16 men</a> (6.4%) use anabolic steroids sometime during their life. Male weightlifters aged 20-39 years, fighters, and security personnel are among the most <a href="https://www.fertstert.org/article/S0015-0282(23)01882-4/pdf">common users of anabolic steroids</a>.</p>
<p>Anabolic steroids contribute to muscle growth and fat loss, but they also affect sexual function, including by reducing the <a href="https://www.fertstert.org/article/S0015-0282(23)01882-4/pdf">size of testicles</a>, reducing or stopping <a href="https://www.fertstert.org/article/S0015-0282(23)01882-4/pdf">sperm production</a>, and causing <a href="https://www.fertstert.org/article/S0015-0282(23)01882-4/pdf">impotence and infertility</a>.</p>
<p>Studies show most <a href="https://doi.org/10.1111/jsm.12890">men start producing sperm again</a> within a year of stopping anabolic steroids. But a <a href="https://doi.org/10.1016/j.fertnstert.2023.09.016">recent study</a> of men who became infertile as a result of anabolic steroids found that for some there is long-term damage to sperm production. </p>
<p>In this study of men who had stopped using anabolic steroids and had a six-month course of hormone treatment to improve sperm production, more than half still produced no sperm at all or very few sperm after six months. </p>
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Read more:
<a href="https://theconversation.com/science-or-snake-oil-do-men-need-sperm-health-supplements-84379">Science or Snake Oil: do men need sperm health supplements?</a>
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<h2>4. Quit smoking and vaping</h2>
<p>We all know tobacco smoking is terrible for our general health but there is now evidence it’s also bad for <a href="https://pubmed.ncbi.nlm.nih.gov/37628668/">male fertility</a> and <a href="https://doi.org/10.1080%2F00325481.2015.1015928">reproductive outcomes</a>.</p>
<p>In the past decade, vaping has become increasingly popular, especially among young adults. More than 500 e-cigarette brands and 8,000 flavours have been <a href="https://www.mdpi.com/2075-1729/13/3/827">commercialised</a>. There is now growing evidence from animal studies that vaping can <a href="https://doi.org/10.3390/life13030827">harm male reproductive health</a> and experts recommend avoiding vaping when <a href="https://www.mdpi.com/2075-1729/13/3/827">trying to conceive</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/562609/original/file-20231130-29-subdcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Man blowing out vape vapour" src="https://images.theconversation.com/files/562609/original/file-20231130-29-subdcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/562609/original/file-20231130-29-subdcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/562609/original/file-20231130-29-subdcw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/562609/original/file-20231130-29-subdcw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/562609/original/file-20231130-29-subdcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/562609/original/file-20231130-29-subdcw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/562609/original/file-20231130-29-subdcw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">We know smoking harms reproductive health, and there’s increasing evidence vaping does too.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>5. Reduce exposure to environmental chemicals</h2>
<p>In our everyday lives we are exposed to many different environmental chemicals – through the products we use, the food we eat, and the air we breathe. So-called <a href="https://doi.org/10.1016/j.fertnstert.2023.10.008">endocrine-disrupting chemicals</a> can reduce the quality of sperm and cause problems with fertility because they can mimic or block male sex hormones. </p>
<p>It’s impossible to avoid these chemicals completely, because they are all around us. But you can take some simple steps to <a href="https://www.yourfertility.org.au/everyone/drugs-chemicals/chemicals-our-environment">reduce your exposure</a>, including:</p>
<ul>
<li><p>washing fruit and vegetables</p></li>
<li><p>eating fewer processed, canned or pre-packaged foods</p></li>
<li><p>drinking from glass or hard plastic bottles, rather than soft plastic bottles</p></li>
<li><p>heating food in a china or glass bowl covered with paper towel or a plate rather than using plastic takeaway containers or those covered with cling wrap. </p></li>
</ul>
<p>To inform men about how to look after their sperm, <a href="https://www.yourfertility.org.au/">Your Fertility</a>, a fertility health promotion program delivered by the Victorian Assisted Reproductive Treatment Authority, teamed up with Melbourne comedian Michael Shafar to create some helpful <a href="https://www.yourfertility.org.au/fertility-week-2022">educational videos</a>.</p>
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Read more:
<a href="https://theconversation.com/considering-using-ivf-to-have-a-baby-heres-what-you-need-to-know-108910">Considering using IVF to have a baby? Here's what you need to know</a>
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<img src="https://counter.theconversation.com/content/217787/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Karin Hammarberg works for the Victorian Assisted Reproductive Treatment Authority which manages the Your Fertility program. </span></em></p>With sperm counts declining world wide, it’s important to know how to keep your sperm as healthy as possible.Karin Hammarberg, Senior Research Fellow, Global and Women's Health, School of Public Health & Preventive Medicine, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1874982022-08-10T15:33:02Z2022-08-10T15:33:02ZMen’s fertility also declines with age — here’s what to know if you’re planning to wait to have kids<figure><img src="https://images.theconversation.com/files/477665/original/file-20220804-25-yu6m7w.jpg?ixlib=rb-1.1.0&rect=0%2C14%2C4992%2C3974&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Fertility tends to decline from 40 onwards.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/sperm-spermatozoa-magnifying-glass-analysis-spermogram-2157696345">Home creator/ Shutterstock</a></span></figcaption></figure><p>While women are often reminded about their “biological clock,” many guys just <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/1467-9566.13116">don’t feel the same pressures</a> when it comes to settling down and starting a family. In fact, a lot of men in their 20s – especially cisgender, heterosexual men – don’t think a great deal about <a href="https://dash.harvard.edu/handle/1/40046518">having children</a> or when they <a href="https://dora.dmu.ac.uk/handle/2086/22039">might want to have children</a>.</p>
<p>This might be because many people think men have all the time in the world when it comes to having children. Exceptional examples such as Mick Jagger – who had a child when he was 73 years old – are often cited to reinforce this argument. But in reality, there are many things men need to bear in mind when it comes to their fertility and starting a family. </p>
<p>In recent decades we have seen a gradual shift towards more people becoming parents later in life. In England and Wales, both men and women are having children later than <a href="https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/livebirths/bulletins/birthcharacteristicsinenglandandwales/2020">ever before in recorded history</a>. Men alone now have children on average aged <a href="https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/livebirths/bulletins/birthcharacteristicsinenglandandwales/2020">nearly 34-years-old</a>, compared to around <a href="https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/livebirths/bulletins/birthcharacteristicsinenglandandwales/2017">29-years-old in the mid-70s</a>. </p>
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<img alt="Quarter life, a series by The Conversation" src="https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/451343/original/file-20220310-13-1bj6csd.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><strong><a href="https://theconversation.com/uk/topics/quarter-life-117947?utm_source=TCUK&utm_medium=linkback&utm_campaign=UK+YP2022&utm_content=InArticleTop">This article is part of Quarter Life</a></strong>, a series about issues affecting those of us in our twenties and thirties. From the challenges of beginning a career and taking care of our mental health, to the excitement of starting a family, adopting a pet or just making friends as an adult. The articles in this series explore the questions and bring answers as we navigate this turbulent period of life.</em></p>
<p><em>You may be interested in:</em></p>
<p><em><a href="https://theconversation.com/online-dating-fatigue-why-some-people-are-turning-to-face-to-face-apps-first-184910?utm_source=TCUK&utm_medium=linkback&utm_campaign=UK+YP2022&utm_content=InArticleTop">Online dating fatigue – why some people are turning to face-to-face apps first</a></em></p>
<p><em><a href="https://theconversation.com/baby-names-why-we-all-choose-the-same-ones-185546?utm_source=TCUK&utm_medium=linkback&utm_campaign=UK+YP2022&utm_content=InArticleTop">Baby names: why we all choose the same ones</a></em></p>
<p><em><a href="https://theconversation.com/body-image-issues-affect-close-to-40-of-men-but-many-dont-get-the-support-they-need-179046?utm_source=TCUK&utm_medium=linkback&utm_campaign=UK+YP2022&utm_content=InArticleTop">Body image issues affect close to 40% of men – but many don’t get the support they need</a></em></p>
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<p>There are <a href="https://pubmed.ncbi.nlm.nih.gov/21652599/">multiple, complex reasons</a> for this – including young people facing more difficulties buying houses and living in an uncertain economic climate, alongside changes in the way people date and form relationships. Another factor is that both women and men are <a href="https://www.rbmojournal.com/article/S1472-6483(13)00501-4/fulltext">staying in education longer</a>, and taking longer to establish careers. Alongside this, people appear to feel more pressure to have children at a time when they can <a href="https://link.springer.com/chapter/10.1007/978-90-481-8969-4_11">give them the “best start” in life</a>.</p>
<p>While some people can have children in their 30s, 40s and beyond with ease, others may struggle. There are often misconceptions that only women face fertility difficulties the older they get but growing evidence suggests that age also affects a man’s fertility, too – <a href="https://www.drfertility.co.uk/pages/does-age-affect-male-fertility">from around about 40 onwards</a>. In fact, age has been shown to <a href="https://link.springer.com/article/10.1186/s12958-015-0028-x">negatively affect sperm quality</a>, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0378512219301343">reduce fertility</a>, and carry a greater likelihood of both <a href="https://link.springer.com/article/10.1186/s12958-015-0028-x">miscarriage</a> and <a href="https://link.springer.com/article/10.1007/s11934-018-0802-3">health conditions</a> in children – particularly <a href="https://link.springer.com/article/10.1186/s12958-015-0028-x">autism, schizophrenia, bipolar disorder and childhood leukaemia</a>. </p>
<p>But this evidence is rarely talked about – and men <a href="https://www.sciencedirect.com/science/article/abs/pii/S001502821202345X">often aren’t aware</a> their fertility can decline as they get older. While this is not a reason to panic – arguably the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4854095/">risks still remain low</a> – it is something to be aware of if you are planning to wait to have kids.</p>
<h2>Improving your odds</h2>
<p>So what can you do then to make sure you have the best chance possible when you do want to have children? There are a couple of factors to take into account.</p>
<p>The first is your lifestyle. Research shows that many different lifestyle factors can affect a man’s fertility. In particular, research suggests avoiding <a href="https://www.tandfonline.com/doi/full/10.1080/14647273.2017.1382733">smoking</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/29713532/">excess alcohol intake</a>, as well as having a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7848840/">healthy diet and BMI</a>, are important for healthy sperm and for fertility. Men (and women) <a href="https://www.youtube.com/watch?v=ETwDCKBaYd4">are encouraged to think about these things</a> – and others such as <a href="https://academic.oup.com/humrep/article/33/9/1749/5066758?login=true">avoiding tight underwear</a>, <a href="https://www.nice.org.uk/guidance/cg156/evidence/full-guideline-pdf-188539453">drugs and steroids</a> – in their teens and 20s.</p>
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<img alt="A group of young men drink beers in a pub." src="https://images.theconversation.com/files/477666/original/file-20220804-1334-shfeux.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477666/original/file-20220804-1334-shfeux.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477666/original/file-20220804-1334-shfeux.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477666/original/file-20220804-1334-shfeux.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477666/original/file-20220804-1334-shfeux.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477666/original/file-20220804-1334-shfeux.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477666/original/file-20220804-1334-shfeux.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Lifestyle factors such as excess drinking can affect fertility.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/people-leisure-friendship-bachelor-party-concept-389227426">Ground Picture/ Shutterstock</a></span>
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<p>But having a healthy lifestyle is only one part of the equation. Another key part is age. Ideally, you want to try to have children before “fertility ageing” becomes a problem – that is, before age may affect your chance of conceiving or the wellbeing of your children. Although many people believe that men can continue having children well into old age, the evidence shows us that this may not necessarily be true – and may also come with risks. This is why it may be important for more young men to start thinking about whether, when and under what circumstances they may want children, and build these ideas into <a href="https://theconversation.com/forget-freezing-sperm-its-time-for-men-to-take-responsibility-for-the-foreplay-of-fatherhood-43753">how they plan and live their life</a>.</p>
<p>Being single is a <a href="https://pubmed.ncbi.nlm.nih.gov/32802369/">key reason</a> why both men and women aren’t able to have children at their ideal time – and why some <a href="https://www.emerald.com/insight/content/doi/10.1108/WWOP-09-2017-0025/full/html">remain childless</a> even if they wanted children. So it’s important to keep fatherhood in mind when navigating dating and relationships. Both <a href="https://journals.sagepub.com/doi/abs/10.1111/j.1467-954X.2010.01924.x">avoiding “settling down”</a> or staying with the wrong person for too long can affect your (and your partner’s) chances of finding the right person to have children with in the future. </p>
<p>Fertility isn’t just down to one person. If you do have a partner, it may be important to consider both of your ages and fertility when considering having kids. A woman’s fertility <a href="https://www.britishfertilitysociety.org.uk/fei/at-what-age-does-fertility-begin-to-decrease/">decreases faster</a> than a man’s does, so having frank and honest conversations about if and when you’d both like to become parents may help you avoid future arguments and disappointments. </p>
<p>New technologies continue to be developed which may help people increase their odds of becoming parents in the middle and older age. In particular, <a href="https://www.emerald.com/insight/publication/doi/10.1108/9781787564831">egg freezing is a growing phenomenon</a> and some suggest <a href="https://jme.bmj.com/content/41/9/775.short?g=w_jme_ahead_tab">sperm freezing in younger adulthood</a> can help men have children later in life but using the best quality sperm. But just because these technologies may make it possible, doesn’t mean you shouldn’t still think about whether and when you want to have children as you begin to plan your adult life.</p>
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<p class="fine-print"><em><span>Caroline Law does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Despite what many men believe, they might not have all the time in the world when it comes to having children.Caroline Law, Senior Research Fellow, De Montfort UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1596922021-06-02T15:07:00Z2021-06-02T15:07:00ZFamily size: why some Nigerian men want more children<figure><img src="https://images.theconversation.com/files/403582/original/file-20210531-28-bh89g7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Men largely determine the fertility rate in Nigeria. These men are drumming for dancers at a festival.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/men-drum-for-dancers-during-the-annual-festival-of-the-news-photo/939233450?adppopup=true">Pius Utomi Ekpei/AFP via Getty Images </a></span></figcaption></figure><p>Fertility levels remain <a href="https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?locations=NG">relatively high</a> in Nigeria. The rate is <a href="https://www.statista.com/statistics/382212/fertility-rate-in-nigeria/#:%7E:text=The%20fertility%20rate%20is%20the,the%20world%20fertility%20rate%20ranking.">slightly over five children</a> per woman. This is <a href="https://www.statista.com/statistics/262884/countries-with-the-highest-fertility-rates/">one of the highest</a> fertility rates in the world. With almost seven children per woman, Niger has the highest rate in the world, followed by Mali. </p>
<p>Many <a href="https://www.tandfonline.com/doi/full/10.1080/26410397.2021.1893890">studies</a> have suggested targeting men in family planning programmes to reduce fertility levels, particularly in patriarchal societies. This is because men wield excessive power that determines contraception use or non-use.</p>
<p>In Nigeria, which is a patriarchal society, the influence of men on fertility behaviour is seen in many ways. For instance, men usually <a href="https://academicjournals.org/article/article1379759046_Kinanee%20and%20Ezekiel-Hart.pdf">make decisions</a> about the number of children a woman will have. </p>
<p>We conducted <a href="https://journals.sagepub.com/doi/abs/10.1177/0272684X19875022">research</a> exploring the contextual factors that influence the attitudes of men towards fertility. These include sociocultural norms, beliefs, preferences and perceptions. Our study involved a range of different ethnic groups in Nigeria. </p>
<p>We collected qualitative data on men’s perceptions about the number of children people were expected to have in their community and the reasons for this. </p>
<p>We also sought to establish who usually wanted to have a high number of children in the family and who determined the number of children among couples. </p>
<p>Nigeria’s population growth is not sustainable. Population growth <a href="https://www.unfpa.org/press/sustainable-development-and-population-dynamics-placing-people-centre">places increasing pressures</a> on resources – such as water, forests and land – contributing to climate change and challenging environmental sustainability. </p>
<p>Among the <a href="https://www.internetworldstats.com/stats8.htm#:%7E:text=Ten%20Countries%20with%20the%20Highest%20Population%20in%20the%20World&text=are%20China%2C%20India%2C%20United%20States,%2C%20Bangladesh%2C%20Russia%20and%20Mexico.">10 largest countries</a> worldwide, <a href="https://www.un.org/en/development/desa/population/events/pdf/other/21/21June_FINAL%20PRESS%20RELEASE_WPP17.pdf">Nigeria is growing</a> the most rapidly. Nigeria’s population, currently the world’s seventh largest, is <a href="https://www.un.org/en/development/desa/population/events/pdf/other/21/21June_FINAL%20PRESS%20RELEASE_WPP17.pdf">projected</a> to surpass that of the United States and become the third largest country in the world shortly before 2050. Nigeria <a href="https://borgenproject.org/nigerias-struggle-overpopulation/">struggles</a> with its population growth. </p>
<p>Our findings showed some of the beliefs and perceptions influencing male fertility in Nigeria. These include religion, polygamy, socioeconomic status, government policy, peer pressure, culture and sex preference. They also vary across ethnic groups. </p>
<p>Thus, there is a need to take into consideration the unique community structures in subsequent population-oriented social policy reviews and implementation to tackle high fertility behaviour in Nigeria.</p>
<h2>Beliefs and perceptions</h2>
<p>We used qualitative data that involved focus group discussions (12 in all) and in-depth interviews (18 in all) from Osun, Enugu and Zamfara. We interviewed men from the country’s three major ethnic groups – Hausa, Igbo and Yoruba.</p>
<p>Across the three states the men involved in the discussions showed that they were knowledgeable about fertility. There were hardly any variations across the major ethnic groups. All placed a high value on large family size – more than four children per woman. </p>
<p>We asked the men how many children they wanted to have. Some wanted to have three or four, while some said such the decision was based on God or Allah’s wish for them. </p>
<p>For the most part, the reasons given for wanting a large number of children were to populate the earth, help with farm work, and to provide old-age support, honour and prestige. </p>
<p>A number of beliefs and perceptions that affected decisions around fertility were mentioned.</p>
<p>Religion was one. Religion plays a prominent role in how many children families have Nigeria. About <a href="https://www.pewresearch.org/fact-tank/2019/04/01/the-countries-with-the-10-largest-christian-populations-and-the-10-largest-muslim-populations/">50% of Nigerians identify themselves as Muslims, while 48.1% identify as Christians</a>. Islam promotes large families and encourages early marriage and a polygamous family system. Christianity prohibits the most effective forms of contraception and does not support abortion.</p>
<p>Polygamy: This is more prevalent in the northern region, where more than <a href="https://www.stearsng.com/article/understanding-the-costs-of-polygamy-in-nigeria">a third of married women</a> reported having one or more co-wives. Through polygamy, the man will have multiple children from many wives. </p>
<p>Socioeconomic status: The economic situation of men was a determining factor in fertility behaviour. An example of this was that if the proportion of men with a nonprofessional occupation (like farming) in the community was high, there was a higher likelihood that the men wanted larger families. If the proportion of men who had at least secondary education in the community was low, they were more likely to have larger families. Peer pressure was another factor. </p>
<p>Government policy: Some mentioned that this encouraged families to have at most four children. Nigeria <a href="http://www.bioline.org.br/request?ep02008">launched a policy</a> of four children per woman in 1988 to stem population growth.</p>
<p>Culture: Culture plays a prominent role. Most cultures in Nigeria encourage many children. No culture supports having only a few. Sex preference, to a large extent, also influences the number of children. A <a href="https://www.magonlinelibrary.com/doi/abs/10.12968/ajmw.2009.3.4.44804?journalCode=ajmw">higher premium</a> is placed on male children. This encourages families to have more children until they have boys. </p>
<p>The respondents also articulated the effects of having a large family. These included being unable to adequately cater for the children. This could lead to children being socially disruptive, malnutrition, as well as high maternal and under-five mortality rates. Others mentioned strain on social and health infrastructure, discrimination against girls’ education, youth delinquency such as teenage pregnancy and sexual vices. </p>
<p>Some of the respondents gave reasons for a small family. The main ones included being able to give children quality education and to avoid poverty. </p>
<h2>Next steps</h2>
<p>To control population growth the government needs to design more interventions to improve education, employment opportunities and the economy. </p>
<p>For example, our study shows that the more the men were educated, the fewer the children they wanted to have. </p>
<p>There is also a need for steps to improve the socioeconomic status of men. The government needs to create more job opportunities. Research has shown that areas of high unemployment rates and low socioeconomic status family sizes are larger. </p>
<p>In addition, the government must run campaigns and programmes explaining the social and economic consequences of high rates of fertility. </p>
<p>Finally, the government must take steps to break down the country’s patriarchal family system so that women are given some autonomy. This can be driven by strengthening and promoting social policies that benefit girls and women such as access to education, employment opportunities and political positions.</p><img src="https://counter.theconversation.com/content/159692/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ololade Grace Adewole works in National Centre for Technology Management</span></em></p><p class="fine-print"><em><span>Kehinde Oluwaseun Omotoso receives funding from National Research Fund, South Africa.</span></em></p><p class="fine-print"><em><span>Sola S. Asa does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The Nigerian government must design more interventions to improve education, employment opportunities and the economy in order to control the country’s population growth.Ololade Grace Adewole, Assistant Chief Planning Officer, National Centre for Technology Management, Obafemi Awolowo UniversityKehinde Oluwaseun Omotoso, DST/NRF SARCHl Chair in Social Policy, University of South AfricaSola S. Asa, Associate Professor of Demography and Social Statistics, Obafemi Awolowo UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1564112021-03-03T13:33:56Z2021-03-03T13:33:56ZMale fertility: how age affects men’s chances of having children<figure><img src="https://images.theconversation.com/files/387500/original/file-20210303-20-zooaxb.jpg?ixlib=rb-1.1.0&rect=160%2C150%2C6412%2C4158&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Men can produce children for longer than women.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/happy-senior-grandparent-give-high-five-1679894521">Shutterstock/fizkes</a></span></figcaption></figure><p>In 2012, proud dad <a href="https://newsfeed.time.com/2012/10/18/worlds-oldest-dad-96-fathers-another-child/">Ramjit Raghav</a> made global headlines when he became a father at the age of 96. He had beaten the record for the world’s oldest dad – a record he’d set himself, two years earlier, at the age of 94.</p>
<p>Older men fathering children is not unknown, especially in the world of celebrities. Rod Stewart became a dad for the eighth time at 66, <a href="https://www.theguardian.com/music/2016/jul/15/mick-jagger-to-become-father-for-the-eighth-time-at-the-age-of-72">Mick Jagger</a> at the age of 72, and <a href="https://news.sky.com/story/bernie-ecclestone-is-a-dad-again-65-years-after-his-first-child-was-born-12019309">Bernie Ecclestone</a> became a father again at the age of 89 in July 2020. Men can produce sperm from puberty to a ripe old age and continue to father children as long as they do so.</p>
<p>Women, on the other hand, have a limited fertile window. Past 51 – the <a href="https://www.nhsinform.scot/illnesses-and-conditions/sexual-and-reproductive/menopause">average age of menopause</a> – they cease to release any eggs and become infertile. Both men and women are delaying having children. The <a href="https://www.ons.gov.uk/peoplepopulationandcommunity/birthsdeathsandmarriages/livebirths/bulletins/birthcharacteristicsinenglandandwales/2017#:%7E:text=The%20average%20age%20of%20first,or%20subsequent%20births%20in%202017.">average age</a> of first-time mothers in the UK is nearly 29 and fathers 33. </p>
<p>The biological difference often lead to discussions of women’s biological clocks running out, while men are under the impression they’ll stay fertile for much longer. But the reality is much more complex than that. There is a growing body of research showing that men’s fertility is hugely affected by age.</p>
<h2>Egg supplies</h2>
<p>As women age, both the number and the quality of her eggs declines. All the eggs a woman will ever have for her reproductive life is determined before she’s born, through a <a href="https://www.ncbi.nlm.nih.gov/books/NBK10008/">processes called oogenesis</a>. </p>
<p>By the 20th week of pregnancy, a female foetus has approximately 6 to 7 million germ cells, all with the potential to turn into eggs. After this, the number of germ cells drops steeply. Those that remain develop into primary oocytes, or immature egg cells.</p>
<p>These immature egg cells go through some changes, then form primordial follicles, each containing an egg. These primordial follicles will remain at this stage until puberty, by which time there are 400,000 to 500,000 left. </p>
<p>At the start of puberty until menopause, groups of primordial follicles are activated and start to mature. Each month, one mature egg cell will ovulate – be released into the Fallopian tube. As the woman ages, the number of follicles continue to decline with age. Those remaining immature eggs can stay at this stage for up to 50 years. During this time, they can accumulate chromosomal errors as they age, increasing the risk of conditions such as Down’s syndrome.</p>
<p>This ageing of the egg cells and the continuing drop in numbers are responsible for the limited fertile window in women. This decline in fertility occurs more steeply <a href="https://www.britishfertilitysociety.org.uk/fei/at-what-age-does-fertility-begin-to-decrease">after the age of 35</a> where she will have roughly 25,000 eggs in her ovaries. By the time she reaches menopause there will be just 1,000 eggs remaining. </p>
<h2>Older fathers</h2>
<p>Men’s fertility doesn’t stop as abruptly as women’s. The testis can still produce the male hormone testosterone and sperm cells, enabling some men to father children in to their 90s.</p>
<p>However, this doesn’t mean men’s fertility is unaffected by age. <a href="https://academic.oup.com/humrep/article/15/8/1703/670811">One study</a> showed after adjusting for female age, conception during a 12-month period was 30% less likely for men over the age of 40 compared with men younger than 30.</p>
<p>Although sperm is still being produced, the quality changes. The number of sperm produced, called the concentration or count, how well the sperm swim, known as their motility, and the shape of the sperm, called their morphology, are all known to change with age.</p>
<figure class="align-center ">
<img alt="A graphic showing sperm swimming towards an egg cell." src="https://images.theconversation.com/files/387501/original/file-20210303-23-mw8gwf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/387501/original/file-20210303-23-mw8gwf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=369&fit=crop&dpr=1 600w, https://images.theconversation.com/files/387501/original/file-20210303-23-mw8gwf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=369&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/387501/original/file-20210303-23-mw8gwf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=369&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/387501/original/file-20210303-23-mw8gwf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=464&fit=crop&dpr=1 754w, https://images.theconversation.com/files/387501/original/file-20210303-23-mw8gwf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=464&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/387501/original/file-20210303-23-mw8gwf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=464&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sperm motility is affected by the man’s age.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/sperm-egg-cell-natural-fertilization-3d-1077682163">Shutterstock/Yurchanka Siarhei</a></span>
</figcaption>
</figure>
<p>One study <a href="https://www.sciencedirect.com/science/article/abs/pii/S0015028213006870?via%3Dihub">examining sperm quality</a> in 5,081 men aged 16.5 to 72.3 years reported ejaculate volume, sperm concentration, sperm motility and sperm morphology didn’t change before the age of 34. However, sperm concentration and the proportion of sperm of normal morphology declined after the age of 40. Sperm motility fell after the age of 43 and ejaculate volume after 45.</p>
<p>In a 2015 <a href="https://reader.elsevier.com/reader/sd/pii/S1568163714001226?token=09837BD9BC1DAD74947C1100EF715EFE8F8AA40131176594FAE7079C464A48EA31124BE51CBAA99C93B8FDC9C615C699">meta-analysis study</a>, using data from 90 studies, male age was associated with a decrease in semen volume, a decrease in total sperm count, a decrease in motility and a decrease in the percentage of normal sperm morphology.</p>
<p>Older fathers are also associated with negative effects on the child. Older men can accumulate <a href="https://academic.oup.com/humrep/article/22/1/180/2939186">damage and mutations</a> in sperm DNA that may result in increased risks of unsuccessful or abnormal pregnancies, because of fertilisation with damaged sperm. The offspring of older fathers show high prevalence of genetic abnormalities, childhood cancers and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3976758/">several neuropsychiatric disorders</a> such as autism, psychosis and bipolar disorders. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-how-can-twins-have-different-fathers-56164">Explainer: how can twins have different fathers?</a>
</strong>
</em>
</p>
<hr>
<p>In a recent study <a href="https://www.bmj.com/content/363/bmj.k4372">in the BMJ</a> men aged 45 years or older had increased odds of fathering infants born premature, of low birth weight, and with a low <a href="https://www.huffingtonpost.co.uk/2014/08/14/what-is-the-apgar-score-your-baby-s-first-health-check-explained_n_7351650.html">Apgar score</a> – a score used to test the health of a newborn – compared with their younger counterparts.
On top of this, the offspring of fathers older than 55 were more likely to require assisted ventilation and admission to a neonatal intensive care unit.</p>
<p>Women’s fertility window is, on average, much shorter than the years men are able to produce sperm. But the negative effect of older age on fertility in women is well documented. </p>
<p>For men, there’s increasing evidence indicating older men have poorer semen quality, increased sperm DNA damage and mutations, leading to less reproductive success. Older men should also be counselled on their offspring’s possible increased risk of certain medical conditions.</p><img src="https://counter.theconversation.com/content/156411/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Carroll does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Older fathers have a lower chance of conceiving and increased chances of negative effects on children.Michael Carroll, Reader / Associate Professor in Reproductive Science, Manchester Metropolitan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1268152019-11-12T22:01:41Z2019-11-12T22:01:41ZLead-tainted water: How to keep homes, schools, daycares and workplaces safe<figure><img src="https://images.theconversation.com/files/301366/original/file-20191112-178494-19xfcz9.jpg?ixlib=rb-1.1.0&rect=191%2C66%2C4500%2C3172&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Health Canada has some of the strongest limits on lead in the world, but they can't be effective without testing and a plan to replace pipes. </span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>We worked behind the scenes with dozens of journalists on “<a href="http://www.globalnews.ca/taintedwater">Tainted Water</a>,” a year-long investigation into lead-contaminated drinking water in Canada. We were shocked by the results.</p>
<p>The journalists, co-ordinated by Concordia University’s Institute for Investigative Journalism, retrieved the results of municipal lead tests from 14 Canadian cities via Freedom of Information Act requests. They also collected water samples by knocking on doors and interviewed people who assumed their water was safe.</p>
<p>As the results poured in, any illusions we had about widespread compliance with lead safety standards for drinking water quickly evaporated.</p>
<h2>The problem with old plumbing</h2>
<p>One-third of water samples, most of them taken from older homes suspected to have lead service lines, exceeded Health Canada’s new guidance of five parts per billion (ppb); 18 per cent exceeded 15 ppb. <a href="https://globalnews.ca/news/6125107/lead-levels-5-canadian-cities-flint-tainted-water/">Five cities</a> — Montréal, Regina, Saskatoon, Prince Rupert, B.C. and Moose Jaw, Sask. — had levels of lead in their water that were comparable with Flint, Mich., during its peak period of water contamination. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/301392/original/file-20191112-178516-18ywhwz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/301392/original/file-20191112-178516-18ywhwz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/301392/original/file-20191112-178516-18ywhwz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/301392/original/file-20191112-178516-18ywhwz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/301392/original/file-20191112-178516-18ywhwz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/301392/original/file-20191112-178516-18ywhwz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/301392/original/file-20191112-178516-18ywhwz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Crews work to replace lead-tainted pipes in Flint, Mich. in 2016.</span>
<span class="attribution"><span class="source">(Jake May/The Flint Journal-MLive.com via AP)</span></span>
</figcaption>
</figure>
<p>In Ontario, the only province that required schools to test their water, <a href="https://globalnews.ca/news/6107982/ontario-schools-daycares-lead-levels/">more than 2,400 schools and daycare centres</a> exceeded the federal guideline.</p>
<p>These results confirm what studies have found over the past 10 years; lead-tainted water is, too often, present in our daycares and <a href="https://doi.org/10.1016/j.watres.2018.04.045">schools</a>, in our workplaces and <a href="https://doi.org/10.1016/j.watres.2013.02.010">homes</a>.</p>
<p>Drinking water that contains five parts per billion of lead — the equivalent to five tablespoons of lead in an Olympic-sized swimming pool — increases the amount of lead circulating in our blood by <a href="https://doi.org/10.1542/peds.2016-1493">20 to 30 per cent</a>; lead in water is the <a href="https://doi.org/10.2166/wh.2013.067">primary source for infants</a> who drink formula made with tap water.</p>
<p>The news wasn’t all bad. Some cities, like Toronto and Ottawa, already use chemicals to reduce leaching of lead from water pipes and, predictably, the amount of lead in drinking water plummeted. Corrosion control also reduces damage to drinking water pipes. Several cities have already begun to replace lead service lines.</p>
<h2>Health impacts of lead</h2>
<p>The amount of lead found in our blood today is much lower than levels found five decades ago. Yet the amount of lead in our bodies, which is mostly stored in our bones, is <a href="https://doi.org/10.1007/978-1-4612-2542-3_1">10- to 100-times</a> higher than levels found in our pre-industrial ancestors. On an evolutionary timescale, we are still heavily lead-exposed.</p>
<p>Scientists have found that lead — a metal so toxic that the World Health Organization said, “there is no safe level” — elevates the risk for various health problems. A pregnant woman who has too much lead in her blood is <a href="https://doi.org/10.1111/1471-0528.12756">more likely to deliver her baby preterm</a>. Minute amounts of lead <a href="https://doi.org/10.1289/EHP5685">diminishes a child’s ability to learn</a>. An uptick in a <a href="https://www.dx.doi.org/10.1016%2Fj.chemosphere.2012.01.017">man’s lead exposure reduces his fertility</a>. </p>
<p>Along with air pollution and smoking, <a href="https://doi.org/10.1016/S2468-2667(18)30025-2">lead irritates the interior lining of blood vessels that feed the heart</a>, causing plaque build-up and elevating the risk of a heart attack in middle-aged and older people.</p>
<h2>A national strategy for safe water by 2030</h2>
<p><a href="https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/water-quality/guidelines-canadian-drinking-water-quality-summary-table.html">Health Canada’s new guideline</a> for unsafe amounts of lead in water — five ppb — is among the strongest in the world, but it is useless unless we test the tap water using a standardized protocol mimicking how people drink the water, and then act decisively on the results.</p>
<p>In 2017, Parliament’s Committee on Environment and Sustainability <a href="https://www.ourcommons.ca/Content/Committee/421/ENVI/Reports/RP9037962/envirp08/envirp08-e.pdf">reviewed</a> the Canadian Environmental Protection Act and recommended expanding rights for transparency and public participation in decision-making about toxic chemicals, like lead. The committee also recommended legally binding and enforceable national standards for drinking water. We agree.</p>
<p>Canadians should not have to rely on investigative reporters to force release of lead tests done by public health agencies or to show that drinking water in some Canadian cities is worse than in Flint, Mich. Likewise, utilities and not reporters should be telling consumers how to best protect themselves from water lead using remedial flushing, lead filters and bottled water.</p>
<p>We call on the federal government to establish a national commission and develop a strategy to achieve safe water for all Canadians by 2030. The lack of safe drinking water in our cities — and in <a href="https://thenarwhal.ca/this-ontario-first-nations-boil-water-advisory-has-been-in-effect-for-25-years/">many First Nations communities</a> — is a threat to public health and will create a public crisis of confidence.</p>
<p>It won’t be easy to fix the aging system of pipes transporting water to our taps, but Canadians should be able to trust that the water we drink is safe.</p>
<p>[ <em><a href="https://theconversation.com/ca/newsletters?utm_source=TCCA&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=expertise">Expertise in your inbox. Sign up for The Conversation’s newsletter and get a digest of academic takes on today’s news, every day.</a></em> ]</p><img src="https://counter.theconversation.com/content/126815/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bruce Lanphear has received funding from the National Institutes of Health, the US Environmental Protection Agency and the Canadian Institutes for Health Research. Dr. Lanphear, who is the current President of the International Society for Children's Health and Environment, has served as an expert witness in lead poisoning cases, but he received no personal payment. </span></em></p><p class="fine-print"><em><span>Marc Edwards receives funding from the National Science Foundation, American Water Works Association, many water utilities and trade organizations. He led the Flintwaterstudy citizen science team, that helped uncover the Flint water crisis, which is the subject of hundreds of lawsuits to which Edwards is a fact witness (i.e., not a party to the lawsuits). His testimony and records related to Flint have been subpoenaed for both civil and criminal lawsuits. He has been outspoken about misconduct by the U.S. Centers for Disease Control, U.S EPA, state governments, and water utilities in relation to handling lead-in-water issues from 2003-2015, and he has defended these agencies' actions since they apologized in 2016 and worked on the Flint recovery. Edwards has testified to the U.S. Congress six times on lead in water issues since 2004. </span></em></p><p class="fine-print"><em><span>Michele Prevost has received research funding from CFI, NSERC, provincial agencies, hospitals, municipalities and technology companies. She has consulted for Canadian provincial and federal ministries of health, education and environment and the U.S. Environmental Protection Agency. Dr. Prevost is a member of the INSPQ committee on microbial standards, of the CSA Z317.1 (plumbing systems in HCF) and BNQ 3660 (distribution systems). Committee work is not retributed.</span></em></p>An investigation showed that five Canadian cities had lead levels in their water on par with those in Flint, Mich. during its peak period of water contamination.Bruce Lanphear, Professor of Children's Environmental Health, Simon Fraser UniversityMarc Edwards, Professor, Department of Civil and Environmental Engineering, Virginia TechMichele Prevost, Professor and Principal Chairholder, NSERC Industrial Chair on Drinking Water, Polytechnique MontréalLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1089102019-02-05T19:15:10Z2019-02-05T19:15:10ZConsidering using IVF to have a baby? Here’s what you need to know<figure><img src="https://images.theconversation.com/files/257135/original/file-20190205-86210-1r11h6n.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Age is the biggest predictor of IVF success, but not all clinics are equal.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/Y3L_ZQaw9Wo">Brooke Cagle</a></span></figcaption></figure><p>If it’s not you, perhaps it’s someone you know. You don’t look infertile, you don’t feel infertile, but after many months (or years) of trying to start a family, followed by several months of monitoring your cycle in a fertility clinic, it’s time to discuss IVF.</p>
<p>This is a big decision. It will impact your time, your finances, your emotions, your relationships and your dreams of being a parent. </p>
<p>Despite the language of “falling pregnant”, inferring absolute simplicity, infertility is a reality for <a href="https://www.health.gov.au/internet/publications/publishing.nsf/Content/womens-health-policy-toc%7Ewomens-health-policy-experiences%7Ewomens-health-policy-experiences-reproductive%7Ewomens-health-policy-experiences-reproductive-maternal%7Ewomens-health-policy-experiences-reproductive-maternal-fert">one in six Australian couples</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/womens-fertility-does-egg-timer-testing-work-and-what-are-the-other-options-109726">Women's fertility: does 'egg timer' testing work, and what are the other options?</a>
</strong>
</em>
</p>
<hr>
<h2>Infertility isn’t picky, but it is ageist!</h2>
<p>A woman’s age is the <a href="https://www.mja.com.au/journal/2017/207/3/assisted-reproductive-technology-australia-and-new-zealand-cumulative-live-birth">single best predictor</a> of IVF success. This is because a woman is born with all the eggs she will ever have, somewhere between one and four million. Our eggs are slowly trickling out of the ovary in a steady stream, until at menopause there are no eggs left. </p>
<p>Despite the fact that almost 400 eggs will begin to grow each month from puberty to menopause, only one egg will survive each month, bursting out of the ovary at ovulation ready to be fertilised.</p>
<iframe src="https://datawrapper.dwcdn.net/jtESL/2/" scrolling="no" frameborder="0" width="100%" height="197"></iframe>
<p>Sperm are an equally critical component of both IVF and natural fertility. </p>
<p>Despite the myth that male fertility is not impacted by age, a growing body of evidence shows men’s age – and lifestyle factors such as excess weight, smoking and heavy drinking – <a href="https://www.racgp.org.au/afp/2017/september/male-infertility/">affect fertility</a>.</p>
<p>Intracytoplasmic sperm injection (ICSI) has been developed so fertilisation in the lab can still be successful even if only one good quality sperm is available. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/most-men-dont-realise-age-is-a-factor-in-their-fertility-too-67785">Most men don't realise age is a factor in their fertility too</a>
</strong>
</em>
</p>
<hr>
<h2>What is the process and how will I feel?</h2>
<p>IVF artificially increases the number of mature eggs ready for fertilisation. Your treatment very much depends on what your infertility diagnosis is, but for most couples undergoing IVF, the process will look a bit like this.</p>
<p><strong>Step 1: ovarian stimulation</strong></p>
<p>The hormone which makes eggs grow (FSH or follicle stimulating hormone) is given by very tiny, self-given injections just under the skin, in high but tailored doses. This creates a hormone tsunami, giving many eggs a chance to ride this wave. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/257143/original/file-20190205-86195-qow55y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/257143/original/file-20190205-86195-qow55y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/257143/original/file-20190205-86195-qow55y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/257143/original/file-20190205-86195-qow55y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/257143/original/file-20190205-86195-qow55y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/257143/original/file-20190205-86195-qow55y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/257143/original/file-20190205-86195-qow55y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Women self-administer the hormone injections.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/481981426?src=zMXyc3de8wm9uknCGlFhLA-1-1&size=huge_jpg">vchal/Shutterstock</a></span>
</figcaption>
</figure>
<p>Using IVF, we can safely increase the number of eggs the woman produces in a cycle without risking multiple births. We take the eggs out of the body, in a process known as egg harvest or oocyte pickup, or OPU. Leaving the eggs in the body for fertilisation incurs an unacceptable risk of having twins, triplets, or more. </p>
<p>These hormones can have some side effects, which are usually mild, and may include tenderness at the injection site, hot flashes, blurred vision, nausea, headache, irritability and restlessness. Your doctor will outline them, and tell you what to monitor.</p>
<p><strong>Step 2: egg harvest (oocyte pickup)</strong></p>
<p>When the eggs are mature (generally up to 18 mm in size) and your estrogen levels are consistent with the egg numbers and size we need, we plan an egg harvest. </p>
<p>A trigger injection is given to finalise egg growth and development, and approximately 36 hours later, we perform the surgical procedure to collect them, ready to put them together with the sperm for in vitro fertilisation (IVF). </p>
<p>This procedure is more like a blood test than open surgery and in many units this procedure is done with pain relief while the female partner is awake. Other units use a light sedative anaesthetic, while they insert a narrow needle and camera (ultrasound) through the vagina to collect the eggs for IVF.</p>
<p><strong>Step 3: in vitro fertilisation (IVF)</strong></p>
<p>Over the next few hours, the embryologists will wash all the viable eggs and prepare them for fertilisation. They are then placed in a dish with thousands of sperm, which were collected previously and frozen, or collected on the same day from your partner. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/257150/original/file-20190205-86213-18qdgf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/257150/original/file-20190205-86213-18qdgf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/257150/original/file-20190205-86213-18qdgf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/257150/original/file-20190205-86213-18qdgf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/257150/original/file-20190205-86213-18qdgf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/257150/original/file-20190205-86213-18qdgf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/257150/original/file-20190205-86213-18qdgf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/257150/original/file-20190205-86213-18qdgf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">ICSI looks something like this.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/ivf-artificial-insemination-realistic-vector-design-1156125265?src=TwMKPKSqfztCJPeUqkfkrQ-1-21">Apl56/Shutterstock</a></span>
</figcaption>
</figure>
<p>Or, if you’re using intracytoplasmic sperm injection (ICSI), the embryologists directly inject one sperm into the cytoplasm of each egg. </p>
<p><strong>Step 4: embryo culture</strong></p>
<p>The day after IVF, the embryologist or nurse will phone you to tell you how many eggs were fertilised.</p>
<p>For the next few days, your embryos will live in a dish, in an oven heated to body temperature. Staff will monitor their growth and development and will eventually pick the right one for transfer back into the womb. </p>
<p>The embryo is gently transferred back into the womb on day five or six, in a process similar to that of a pap test. If you have many healthy embryos at this stage, they can be frozen for use later. </p>
<h2>Now you wait</h2>
<p>About a week-and-a-half to two weeks after your embryo was transferred, we can test to see if it’s attached to the womb. A simple blood test, or even home pregnancy test, will detect levels of human chorionic gonadotrophin (HCG), a sign that you are finally pregnant.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/257149/original/file-20190205-86220-n16iwn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/257149/original/file-20190205-86220-n16iwn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/257149/original/file-20190205-86220-n16iwn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/257149/original/file-20190205-86220-n16iwn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/257149/original/file-20190205-86220-n16iwn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/257149/original/file-20190205-86220-n16iwn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/257149/original/file-20190205-86220-n16iwn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">There’s so much waiting when you go through IVF.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/1081646393?src=MkcCgBb3qlTKDrT3OCxh-A-1-10&size=huge_jpg">Rawpixel/Shutterstock</a></span>
</figcaption>
</figure>
<p>For some, the test will be negative. If they have frozen embryos, they can try again without needing to take more injections and have a surgical procedure. </p>
<p>Others will receive a diagnosis after learning something about their eggs, sperm and embryos, which can help the IVF team adjust the cycle plan and improve the couple’s outcomes in future cycles. </p>
<p>For some, it was the last time they were going to try IVF, or fertilisation didn’t occur, or an embryo transfer could not be done. Disappointment, frustration and grief becomes part of the experience and couples may need support and counselling. </p>
<p>For many, a positive pregnancy test is the outcome. But there is still more waiting; after all, you are still 38 weeks away from delivery. A small number of pregnancies miscarry or are lost so support in early pregnancy and good obstetric care is vital. </p>
<h2>How much does it cost?</h2>
<p>The cost of IVF is hugely variable, and is dependent on your level of private health cover. The out of pocket costs, even with the highest level of cover may reach A$9,000 for the first cycle. And each test and process will change the price. </p>
<p>Sit down with your specialist and ask “can you talk me through all of the costs associated with this round of treatment?” and have them break it down.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/women-now-have-clearer-statistics-on-whether-ivf-is-likely-to-work-81256">Women now have clearer statistics on whether IVF is likely to work</a>
</strong>
</em>
</p>
<hr>
<h2>How do you find the right clinic?</h2>
<p>There is a big difference in the quality of fertility care you can receive across Australia, with some clinics having dramatically higher success rates than others. </p>
<p>But keep in mind some clinics may not show all the data. They may quote the pregnancy rates for “every started IVF cycle” or for “every embryo transfer”, meaning the cycles where there is no embryo to transfer are excluded – thus making the rates look unrealistically good. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/257148/original/file-20190205-86228-5es6dh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/257148/original/file-20190205-86228-5es6dh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/257148/original/file-20190205-86228-5es6dh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/257148/original/file-20190205-86228-5es6dh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/257148/original/file-20190205-86228-5es6dh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/257148/original/file-20190205-86228-5es6dh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/257148/original/file-20190205-86228-5es6dh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Many factors affect a couple’s success rate.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/rQTNkcUT8uk">Tina Bo</a></span>
</figcaption>
</figure>
<p>Despite the desire to shop for price, asking the clinic specifically about your chance of taking home a healthy baby in their clinic, and finding a health care provider you feel comfortable with is key. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/five-traps-to-be-aware-of-when-reading-success-rates-on-ivf-clinic-websites-68806">Five traps to be aware of when reading success rates on IVF clinic websites</a>
</strong>
</em>
</p>
<hr>
<p>Your personal success may not be equal across two clinics, and you may save yourself money by finding a clinician and clinic with high success rates, and with a specialist who specialises in your condition, whether it’s <a href="https://theconversation.com/explainer-what-is-polycystic-ovary-syndrome-37203">polycystic ovary syndrome</a> (PCOS), <a href="https://theconversation.com/au/topics/endometriosis-2405">endometriosis</a>, or something else. </p>
<p>Never be afraid to ask as many questions as you have, and to ask for clarity when you don’t understand. Undertaking IVF is a big step.</p><img src="https://counter.theconversation.com/content/108910/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Louise Hull owns no shares in any IVF companies. I work independently in private practice in North Adelaide and have an affiliation with REPROMED for embryology services. I also work in New Zealand at Genea-Oxford Fertility.
I am an Associate Professor at The University of Adelaide. I have several small NGO grants for endometriosis and am a CIC on an NHMRC grant for implantation.</span></em></p><p class="fine-print"><em><span>Hannah Brown does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>If you’re one of the one in six Australian couples experiencing infertility, you’ve probably thought about IVF. Here’s a step by step breakdown of how it all works.Hannah Brown, Chief Science Storyteller, South Australian Health & Medical Research InstituteLouise Hull, Associate Professor and Fertility and Conception Theme Leader, The Robinson Research Institute, University of Adelaide, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1096832019-01-11T13:00:51Z2019-01-11T13:00:51ZHow men’s damaged sperm could play significant role in recurrent miscarriage<figure><img src="https://images.theconversation.com/files/253257/original/file-20190110-43538-1t1ba9z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Shows spunk, but trouble down the line.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/human-sperm-selection-sorting-reproductive-concept-167714144?src=BKZ7HK6K5lSML7UQVeta3A-1-6">Lightspring/Shutterstock</a></span></figcaption></figure><p>It’s an unfortunate fact that one in four pregnancies will end in a miscarriage, typically <a href="https://www.nct.org.uk/pregnancy/miscarriage/miscarriage-your-questions-answered">within the first 12 weeks of pregnancy</a>. In most cases, this will be a single, one-off event with the underlying biological cause unknown. However, around 1% of couples will suffer the agony that is recurrent miscarriage. </p>
<p>Recurrent miscarriage is typically defined as the <a href="https://www.tommys.org/pregnancy-information/pregnancy-complications/baby-loss/miscarriage/types-miscarriage/recurrent-miscarriage">loss of three or more pregnancies in a row</a>. As the mother carries the pregnancy, the traditional belief has been that the underlying cause of miscarriage resides with her. But maternal factors such as hormone imbalance or an inability for the womb to support the pregnancy <a href="https://www.rcog.org.uk/globalassets/documents/guidelines/gtg_17.pdf">only account for about half</a> of recurrent miscarriages. It’s clear, then, that other unknown factors apart from maternal health play a significant role in miscarriage risk. This lack of understanding has lead researchers to investigate whether the quality of a father’s sperm may be involved.</p>
<h2>Healthy fathers, healthy sperm</h2>
<p>Before becoming pregnant, many women will assess and modify their current lifestyle choices, for example drinking or smoking less, in order to ensure a healthy pregnancy. But the health of the father at the time of conception is one factor that is often overlooked. We now know that <a href="https://www.nhs.uk/common-health-questions/mens-health/how-can-i-improve-my-chances-of-becoming-a-dad">the quality of a man’s sperm</a> is directly linked to his health. </p>
<p>Excessive alcohol consumption, smoking, stress – and even the type of underpants he wears – <a href="https://theconversation.com/why-men-need-to-think-about-their-fertility-too-72063">can all affect the quality of a man’s sperm</a>. One of the biggest factors affecting sperm quality is obesity. In many countries, while rates of obesity <a href="https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight">have been increasing</a>, male fertility <a href="http://www.independent.co.uk/news/science/scientists-warn-of-sperm-count-crisis-8382449.html">has been declining</a>. Studies in both men and mice show that sperm from overweight males are less motile, are less likely to fertilise an egg and are <a href="https://rep.bioscientifica.com/view/journals/rep/154/4/REP-17-0161.xml">less likely result in a healthy birth</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-men-need-to-think-about-their-fertility-too-72063">Why men need to think about their fertility too</a>
</strong>
</em>
</p>
<hr>
<h2>Sperm DNA fragmentation</h2>
<p>The prime goal of sperm is to fertilise the egg and pass on the father’s genes to the next generation. It is therefore essential that the DNA contained within the sperm is not damaged or fragmented. Studies have shown that factors such as poor diet, being overweight, smoking, infection and pollution <a href="https://www.reproductivehealthgroup.co.uk/fertility-treatments/assessments/men/dna-fragmentation/">all increase how fragmented the DNA is</a> within sperm. As sperm cannot repair their damaged DNA, high levels of sperm DNA fragmentation is viewed as a leading cause of infertility in men. </p>
<p>Researchers now believe that high levels of sperm DNA fragmentation are also linked with increased risk of miscarriage and <a href="http://clinchem.aaccjnls.org/content/65/1/161">a recent study</a> demonstrated a link between sperm DNA fragmentation and recurrent miscarriage. </p>
<p>Researchers from Imperial College London studied the quality of sperm in men whose partners had suffered with recurrent miscarriage. They then compared those sperm with sperm from men whose partners had not experienced miscarriage. They saw that sperm DNA fragmentation levels were twice as high in men whose partners suffered with recurrent miscarriage than in the control group. </p>
<p>The researchers also found that the levels of a group of molecules called “reactive oxygen species” were four times higher in men with DNA damaged sperm. Reactive oxygen species are produced naturally by every cell, and small amounts are necessary for male reproduction. However, at higher concentrations, reactive oxygen species <a href="https://tdlpathology.com/services-divisions/tdl-andrology/reactive-oxygen-species-and-male-infertility/">can damage sperm cells and their DNA</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/253255/original/file-20190110-43532-74yn7g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/253255/original/file-20190110-43532-74yn7g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/253255/original/file-20190110-43532-74yn7g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/253255/original/file-20190110-43532-74yn7g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/253255/original/file-20190110-43532-74yn7g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/253255/original/file-20190110-43532-74yn7g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/253255/original/file-20190110-43532-74yn7g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Winner shows spunk, but trouble may be down the line.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hand-drawing-sperm-on-blackboard-464817722?src=ujTOqcIG4N3pr6Tq9Lf9Ow-1-0">Piya Kunkayan/Shutterstock</a></span>
</figcaption>
</figure>
<p>The researchers also noted that the men whose partners suffered from recurrent miscarriage were also heavier than the control men as well as older. Recently, there has been a lot of interest <a href="https://www.mayoclinic.org/healthy-lifestyle/getting-pregnant/expert-answers/paternal-age/faq-20057873">in the relationship</a> between a father’s age, the quality of his sperm and the health of his offspring. As men produce sperm throughout their lifetime, the belief has been that age does not affect a man’s fertility. However, recent studies have suggested that a father’s age at the time of conception might affect the health of his children. </p>
<p>Some studies <a href="https://www.fertstert.org/article/S0015-0282(16)63091-1/pdf">have shown</a> that for men over 40, there is an increased risk for miscarriage, rare birth defects, autism, schizophrenia and some types of cancer such as leukaemia. Studies in mice and humans also suggests that poor paternal diet (too much or too little) <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5920283/">can influence</a> the long-term health of offspring, increasing their chances of developing obesity, diabetes and/or heart disease.</p>
<p>The link between a male’s health and well-being of a male and the quality of his sperm is now well established. It is also becoming apparent that sperm quality influences a range of factors including a man’s fertility, the likelihood of him becoming a father and even the long-term health of his children. However, more research is needed to understand the links between the health of a father, the quality of his sperm and the well-being of his offspring. </p>
<p>Much of the fundamental research to date has been conducted in animals. As such, it is vital that we now establish whether the same effects are seen in humans. What is clear though is that both prospective parents in couples who intend on becoming parents should assess their current lifestyle habits to maximise their chances of a healthy pregnancy.</p><img src="https://counter.theconversation.com/content/109683/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Watkins current research is funding by the Biotechnology and Biological Sciences Research Council (BBSRC). </span></em></p>Traditional belief has held that the underlying cause of miscarriage can be found in mothers, but half of recurrent miscarriages have another cause.Adam Watkins, Assistant Professor, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1073752019-01-07T14:28:55Z2019-01-07T14:28:55ZClimate change: effect on sperm could hold key to species extinction<figure><img src="https://images.theconversation.com/files/252638/original/file-20190107-32139-y9hdya.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/skull-on-desert-58522480?src=5RTUr9LQgKjOeuj47ESMcw-1-5">Wong Yu Liang/Shutterstock</a></span></figcaption></figure><p>Since the 1980s, <a href="https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(17)30082-7/fulltext">increasingly frequent and intense heatwaves</a> have contributed to more deaths than any other extreme weather event. The fingerprints of extreme events and climate change are widespread in the natural world, where populations are showing stress responses.</p>
<p>A common fingerprint of a warmer world is a range shift, where the distribution of a species moves to higher altitudes or migrates toward the poles. A review of several hundred studies found an <a href="https://www.ncbi.nlm.nih.gov/pubmed/21852500">average shift of 17km poleward, and 11 metres upslope</a>, every decade. However, if temperature changes are too intense or lead species to geographic dead ends, local extinctions occur in the heat.</p>
<p>In 2003, <a href="https://www.ncbi.nlm.nih.gov/pubmed/12511952" title=") of climate change on natural populations. [Significant and simultaneous stress responses](https://www.ncbi.nlm.nih.gov/pubmed/22257223 "">80% of relevant studies found the fingerprints</a> were seen among species, from grasses to trees and molluscs to mammals. Some migrated, some changed colour, some altered their bodies and some shifted their life cycle timings. A recent review of more than 100 studies found <a href="http://science.sciencemag.org/content/348/6234/571">8-50% of all species</a> will be threatened by climate change as a result. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/HCYGxViPiPA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>High temperatures and extinctions</h2>
<p>Currently, we have a <a href="https://www.ncbi.nlm.nih.gov/pubmed/23075836">disturbingly limited knowledge</a> of which biological traits are sensitive to climate change and therefore responsible for local extinctions. However, a potential candidate is male reproduction, because a range of medical and agricultural studies <a href="https://pdfs.semanticscholar.org/2291/2f5bb3a55579381a5e92cab3a142f94639a1.pdf">in warm blooded animals</a> have shown that male infertility happens during heat stress.</p>
<p>However, until recently this had <a href="https://www.ncbi.nlm.nih.gov/pubmed/16033555">rarely been explored outside fruit flies</a> in cold blooded animals. This is despite the fact that ectotherms – organisms that rely on heat in their environment to maintain a suitable body temperature – comprise most of biodiversity. Astonishingly, nearly <a href="https://www.ncbi.nlm.nih.gov/pubmed/26034274">25% of all species</a> are thought to be a beetle.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/252633/original/file-20190107-32124-12s9wfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/252633/original/file-20190107-32124-12s9wfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/252633/original/file-20190107-32124-12s9wfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=753&fit=crop&dpr=1 600w, https://images.theconversation.com/files/252633/original/file-20190107-32124-12s9wfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=753&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/252633/original/file-20190107-32124-12s9wfx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=753&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/252633/original/file-20190107-32124-12s9wfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=946&fit=crop&dpr=1 754w, https://images.theconversation.com/files/252633/original/file-20190107-32124-12s9wfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=946&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/252633/original/file-20190107-32124-12s9wfx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=946&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The red flour beetle. The ubiquity of beetles prompted biologist J.B.S. Haldane to say that God has ‘an inordinate fondness for beetles’.</span>
<span class="attribution"><span class="source">Martin Taylor</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The red flour beetle (<em>Tribolium castaneum</em>) is a useful ectotherm for <a href="https://www.ncbi.nlm.nih.gov/pubmed/18429767">large experiments on reproduction</a>, as they can go from egg to adult in a month at 30°C. Females can store male sperm in specialised organs called spermathecae and they only need to keep 4% of a single ejaculate to enable them to produce offspring for up to 150 days.</p>
<p>To look at the <a href="https://www.nature.com/articles/s41467-018-07273-z">impact of heatwaves on reproduction</a>, beetles were exposed to either standard control conditions or five-day heatwave temperatures, which were 5°C to 7°C above their preferred temperature. Afterwards, beetles mated and a variety of experiments looked for damage to their reproductive success, sperm form and function, and offspring quality.</p>
<p>We found that 42°C heatwave temperatures halved the number of offspring males could produce relative to 30°C, with some males failing to produce any and mature sperm in female storage also experiencing damage from heatwaves. However, the reproductive output of pairs where only the females endured a five-day heatwave event was similar in all temperatures.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/249969/original/file-20181211-76971-k69dg2.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249969/original/file-20181211-76971-k69dg2.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/249969/original/file-20181211-76971-k69dg2.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=250&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249969/original/file-20181211-76971-k69dg2.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=250&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249969/original/file-20181211-76971-k69dg2.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=250&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249969/original/file-20181211-76971-k69dg2.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=314&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249969/original/file-20181211-76971-k69dg2.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=314&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249969/original/file-20181211-76971-k69dg2.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=314&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Heated males (B) had less sperm (stained green) and relatively more dead sperm (stained red) than control males (A).</span>
<span class="attribution"><span class="source">Kris Sales</span>, <span class="license">Author provided</span></span>
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<p>The decline was likely due to a combination of males becoming worse at mating, less sperm being transferred, less sperm transferred being alive, less sperm being kept in the females’ spermathecae and more sperm being damaged and infertile.</p>
<p>Two results were particularly concerning. These beetles, and many cold-blooded animals, can live for years and are likely to see multiple heatwaves. When we exposed males to two heatwave events, ten days apart, their offspring production was less than 1% of that of unheated males. </p>
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Read more:
<a href="https://theconversation.com/wildlife-winners-and-losers-in-britains-summer-heatwave-100408">Wildlife winners and losers in Britain's summer heatwave</a>
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<p>This suggests that successive heatwaves can compound the damage of previous ones. The damage to offspring longevity and male fertility was another effect which was compounded over successive generations, and could lead to spiralling population declines.</p>
<p>Knowing what aspects of biology higher temperatures could compromise is essential to understanding how climate change affects nature. Hopefully, this new knowledge can help predict which species are most likely to be vulnerable, allowing conservationists to prepare for the trouble ahead.</p><img src="https://counter.theconversation.com/content/107375/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kris Sales does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Climate change threatens to cause mass extinctions – but how, exactly? New research suggests male fertility may be the weakest link.Kris Sales, PhD Candidate in evolution, behaviour, ecology and entomology, University of East AngliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1059622018-11-01T04:10:31Z2018-11-01T04:10:31ZTick-tock – for healthy mums and kids, dad’s age counts<figure><img src="https://images.theconversation.com/files/243392/original/file-20181101-173890-vylh3f.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's not just women who need to consider their age when planning a family.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/LVxLkEprd10">rawpixel</a></span></figcaption></figure><p>Women are regularly reminded of their ticking biological clock. It turns out men should also pay attention to age when it comes to having a family. </p>
<p>A <a href="http://www.bmj.com/content/363/bmj.k4372">new study</a> published today in the British Medical Journal provides persuasive evidence that children – and pregnant mums – are more likely to have health problems when dads are older. </p>
<p><a href="https://www.sciencedirect.com/science/article/pii/S1521690X13001127?via%3Dihub">Men’s fertility declines with age</a>, but not as sharply as women’s. Men can continue to father children into later life – as Mick Jagger and other celebrity fathers demonstrate. </p>
<p>But it takes longer to get pregnant. <a href="https://www.ncbi.nlm.nih.gov/pubmed/14704244">One study</a> in European men showed a 50% lower chance of conceiving after a year of trying at age 35, compared with men younger than 25. </p>
<p>Plus, women with partners age 35 and older may be more likely to experience <a href="https://academic.oup.com/aje/article/161/9/816/79775">miscarriage</a> than those with younger partners.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/most-men-dont-realise-age-is-a-factor-in-their-fertility-too-67785">Most men don't realise age is a factor in their fertility too</a>
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<h2>Higher odds of premature birth</h2>
<p>The <a href="http://www.bmj.com/content/363/bmj.k4372">latest study</a> shows that the chances of pregnancy and birth problems are also increased when dads are older. </p>
<p>Researchers at Stanford University in California analysed data on all 40 million live births in the United States between 2007 and 2016 to look at how paternal age affects outcomes for the infant and the mother.</p>
<p>As the father’s age increased, so did the chances of the infant being born prematurely, having a low birth weight, or requiring medical intervention after delivery, such as assisted ventilation, admission to neonatal intensive care, or antibiotics.</p>
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<img alt="" src="https://images.theconversation.com/files/243395/original/file-20181101-173913-1kvyt2h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/243395/original/file-20181101-173913-1kvyt2h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243395/original/file-20181101-173913-1kvyt2h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243395/original/file-20181101-173913-1kvyt2h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243395/original/file-20181101-173913-1kvyt2h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243395/original/file-20181101-173913-1kvyt2h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243395/original/file-20181101-173913-1kvyt2h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">It takes dads over 35 longer to conceive than those under 25.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/jVXWtTYQHW8">Katie Emslie</a></span>
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<p>When fathers were aged 45 years or more, their children had 14% higher odds of being born premature (less than 37 weeks) and their babies had a 14% greater risk of low birth weight (less than 2.5kg) than when fathers were aged 25 to 34 years. </p>
<p>Infants with fathers aged 45 years or more were also 14% more likely to be admitted to a neonatal intensive care unit, and 18% more likely to have seizures. </p>
<p>If the father was 55 years or older, newborns also tended to score less well on the Apgar test used to assess the health of a child at birth. </p>
<p>These effects were present after adjusting for the mother’s age, smoking, race, education, and number of prenatal visits.</p>
<h2>Future risk of disease</h2>
<p>These latest findings add to <a href="https://www.sciencedirect.com/science/article/pii/S0015028216630911">earlier studies</a> showing older age in fathers is linked with a variety of health conditions affecting the offspring. </p>
<p>Scientists in Denmark have calculated the chances of congenital problems linked to older fatherhood and show that <a href="https://www.sciencedirect.com/science/article/pii/S0015028216630911">several conditions</a> become more prevalent. These include rare developmental conditions such as achondroplasia (dwarfism) and cleft palate. </p>
<p>Cancer rates among offspring also seem to rise as dads become older.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-men-need-to-think-about-their-fertility-too-72063">Why men need to think about their fertility too</a>
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<p>Arguably the most concerning impact is on neurodevelopment and mental health. Offspring of older fathers have an <a href="https://jamanetwork.com/journals/jamapsychiatry/fullarticle/1814892">increased risk</a> of schizophrenia, mental retardation, and autism spectrum disorders. </p>
<p>The risk of schizophrenia increases by 47% when fathers are over 45 years old. </p>
<p>The rate of childhood autism increases by 80% when dads conceive after age 45. </p>
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<img alt="" src="https://images.theconversation.com/files/238289/original/file-20180927-48634-1c0kcp4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238289/original/file-20180927-48634-1c0kcp4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=200&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238289/original/file-20180927-48634-1c0kcp4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=200&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238289/original/file-20180927-48634-1c0kcp4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=200&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238289/original/file-20180927-48634-1c0kcp4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=251&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238289/original/file-20180927-48634-1c0kcp4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=251&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238289/original/file-20180927-48634-1c0kcp4.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=251&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<h2>So what’s going on?</h2>
<p>Changes in the <a href="https://www.sciencedirect.com/science/article/pii/S1521690X13001127?via%3Dihub">sperm of older men</a> are likely to contribute. The number of defective sperm containing DNA mutations <a href="https://www.nature.com/articles/nature11396">increase steadily</a> every year as men age. These arise as exposure to radiation, environmental toxins, alcohol and smoking take their toll. </p>
<p>Ageing itself results in less testosterone and a decline in the number and function of testicular cells. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/243396/original/file-20181101-173890-1cwvgjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243396/original/file-20181101-173890-1cwvgjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243396/original/file-20181101-173890-1cwvgjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243396/original/file-20181101-173890-1cwvgjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243396/original/file-20181101-173890-1cwvgjv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243396/original/file-20181101-173890-1cwvgjv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243396/original/file-20181101-173890-1cwvgjv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Most older dads won’t have fertility problems.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/EQlTyDZRx7U">Picsea</a></span>
</figcaption>
</figure>
<p>However, genetics isn’t the full explanation. In particular, increased risk of psychiatric illness <a href="https://www.nature.com/articles/ng.3577">doesn’t seem to be due</a> to spontaneous mutations in sperm DNA. While mutations contribute, they account for only about 10% to 20% of the effect. </p>
<p>Another possibility is that genetic risk factors naturally more prevalent in men destined to be older fathers might be passed on to their offspring, rather than new mutations.</p>
<h2>Mothers also at risk</h2>
<p>The <a href="http://www.bmj.com/content/363/bmj.k4372">latest data</a> showed negative effects of delayed fatherhood not just for the infants, but also the pregnant mothers. </p>
<p>The risk of gestational diabetes for pregnant women increased in line with the age of the father, with women carrying the child of a man aged 55 years or older having a 34% higher odds of gestational diabetes. </p>
<p>The researchers estimate that around 13% of premature births and 18% of gestational diabetes in pregnancies associated with older fathers were attributable to the advanced age of the father.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/whats-the-point-of-sex-its-communication-at-a-biological-level-67847">What's the point of sex? It's communication at a biological level</a>
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</em>
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<p>This is hard to reconcile with a genetic explanation. Other biological effects of seminal fluid on pregnancy health may be to blame. </p>
<p>The female immune system responds to seminal fluid by <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/aji.12107">generating immune tolerance</a>, which protects against inflammatory exposures that can harm the fetus. Human seminal fluid <a href="https://www.sciencedirect.com/science/article/pii/S0015028216625384?via%3Dihub">contains signals</a> known to stimulate the female immune response, but it’s not yet proven whether these factors decline as men age. </p>
<h2>What does this all mean for men contemplating fatherhood?</h2>
<p>Most older dads don’t have fertility problems and can father babies without serious physical or developmental problems. </p>
<p>Overall, the father’s age is substantially less important than the mother’s age, and generally the pregnancy disorders and infant health problems are rare. So the current research evidence doesn’t justify dissuading older men from becoming fathers.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/243398/original/file-20181101-173916-1xqpmo1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243398/original/file-20181101-173916-1xqpmo1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243398/original/file-20181101-173916-1xqpmo1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243398/original/file-20181101-173916-1xqpmo1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243398/original/file-20181101-173916-1xqpmo1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243398/original/file-20181101-173916-1xqpmo1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243398/original/file-20181101-173916-1xqpmo1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The children of most older dads will be fine.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/MCgXu-RyhGQ">Brittany Simuangco</a></span>
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<p>But the medical community must do a better job of communicating to couples an understanding of the risks of advanced paternal age. </p>
<p>Most importantly, we must include men in conversations about pregnancy planning and preconception care, to ensure all couples have the best chance of raising a healthy child.</p><img src="https://counter.theconversation.com/content/105962/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sarah Robertson receives funding from the NHMRC and ARC.</span></em></p>A new study shows that as the father’s age increases, so too the chances of the baby being born prematurely, having a low birth weight, or requiring medical intervention after delivery.Sarah Robertson, Professor and Director, Robinson Research Institute, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/870472017-12-07T15:29:17Z2017-12-07T15:29:17ZThe invisible infertile: how cultural beliefs can shape statistics<figure><img src="https://images.theconversation.com/files/197183/original/file-20171130-30937-19b50ck.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">IVF</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/vitro-fertilisation-ivf-macro-concept-shallow-193564313?src=cLxkJwEeV9bb6svlAcYl-g-3-11">ShutterstockNevodka</a></span></figcaption></figure><p>Reproductive health is now <a href="http://www.who.int/reproductivehealth/publications/gender_rights/srh-rights-comment/en/">seen as a basic human right</a>. This includes the ability to have children.
Large-scale population surveys are used to identify infertility and help ensure the rights of those who are struggling to conceive. But our research has revealed some people–particularly those who are already marginalised–are falling through the gaps.</p>
<p>An <a href="http://www.who.int/bulletin/volumes/88/12/10-011210/en/">estimated 15%</a> of couples worldwide are infertile. But measuring infertility across populations is not easy, especially when some social groups are under the radar of survey data sources. </p>
<p>In <a href="https://academic.oup.com/heapol/advance-article-abstract/doi/10.1093/heapol/czx148/4563650">our analysis</a> of survey tools, we identify these people as the “invisible infertile”. The suffering of the invisible infertile is twofold. Those who cannot have the children they desire may experience a wide range of issues, ranging from shame and stigma to financial ruin. But because their infertility is invisible to public agencies, they may not receive the medical care and social support that they so dearly need.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/197184/original/file-20171130-30919-znjliz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/197184/original/file-20171130-30919-znjliz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=391&fit=crop&dpr=1 600w, https://images.theconversation.com/files/197184/original/file-20171130-30919-znjliz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=391&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/197184/original/file-20171130-30919-znjliz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=391&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/197184/original/file-20171130-30919-znjliz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=491&fit=crop&dpr=1 754w, https://images.theconversation.com/files/197184/original/file-20171130-30919-znjliz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=491&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/197184/original/file-20171130-30919-znjliz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=491&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A negative pregnancy test.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/pregnancy-negative-test-desperate-couple-young-639540673?src=ZKB0K1pXGzbRlLwrM085mw-1-1">Shutterstock/golubovystock</a></span>
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<h2>Who’s missing?</h2>
<p>In the US, a series of family growth surveys, called the Integrated Fertility Survey Series (IFSS), has collected data on fertility since the 1950s. Men were excluded from these family growth surveys in the US until 2002. No large-scale population data on American men and reproduction exist prior to the 21st century. Women were the primary source of information on everything from condom use to impotence. </p>
<p>In other words, men’s experiences and perspectives were entirely missing from the survey series until the start of this century. Let that sink in. </p>
<p>Women of colour and single and divorced women were excluded from the first wave of the IFSS. Single childless women were excluded until 1982. </p>
<p>In the IFSS, participants were presumed to be heterosexual until questions were added in the last decade to allow respondents to self-identify as LGBTQ.</p>
<p>Meanwhile the <a href="https://dhsprogram.com/">Demographic and Health Surveys</a>, used in 90 low and middle-income countries around the world for nearly 40 years, investigate fertility and family planning. But none of the questions ask explicitly about infertility. </p>
<p>Researchers piece together infertility statistics using marital and pregnancy histories. Yet these estimates are designed to be conservative measures, and are therefore likely to be low. Previous research has also shown that people may suspect infertility well before they would be identified as infertile in these sorts of estimates. Therefore, the estimates are particularly likely to be low when compared to how people view their own fertility. </p>
<h2>Cultural beliefs shape statistics</h2>
<p>As the examples above show, men, racial and ethnic minorities and LGBTQ families have been explicitly excluded from some survey data. We also know single women were excluded from early population surveys and marriage rates are lower for people with <a href="https://www.ncbi.nlm.nih.gov/pubmed/27265773">disabilities</a> and <a href="http://www.pewresearch.org/fact-tank/2017/09/14/as-u-s-marriage-rate-hovers-at-50-education-gap-in-marital-status-widens/">lower-income individuals</a>. </p>
<p>It is safe to speculate that the data does not accurately capture the prevalence of infertility among those with disabilities, chronic illness and lower incomes. </p>
<p>Survey tools are not objective measures. They reflect a cultural context which prizes the fertility of some people and discourages the fertility of others. Sampling practices and questionnaire design mirror our social values. The reproductive health of white, Western middle and upper-class heterosexual married women is prized and their infertility acknowledged. The invisible infertile fall outside of this ideal. </p>
<p>Demographic surveys are funded and administered by wealthy Western nations. In the West, strong international policy focus has been placed on fertility reduction in low and middle-income countries. These interests overlook the <a href="https://academic.oup.com/humrep/article/27/5/1383/696393">physical, emotional, economic and social devastation</a> tied to infertility and childlessness</p>
<p>The omission of men from survey samples could perhaps be chalked up to broader cultural beliefs about reproduction as “women’s work”. But infertile men have no doubt suffered stigma and confusion in navigating the medical system because male infertility is generally invisible.</p>
<p>The invisibility of marginalised social groups in infertility tracking reflects broader social beliefs about who can and should reproduce. The offspring of privileged social groups are seen as a boon to society. The offspring of marginalised groups are perceived as a burden.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/197186/original/file-20171130-30923-1xm8t4s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/197186/original/file-20171130-30923-1xm8t4s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/197186/original/file-20171130-30923-1xm8t4s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/197186/original/file-20171130-30923-1xm8t4s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/197186/original/file-20171130-30923-1xm8t4s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/197186/original/file-20171130-30923-1xm8t4s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/197186/original/file-20171130-30923-1xm8t4s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Gynecologist showing to young couple fetus ultrasound.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/gynecologist-showing-young-married-couple-fetus-281151830">Shutterstock/photographee.eu</a></span>
</figcaption>
</figure>
<p>Demographers, social scientists, medical professionals, public health researchers and humanitarians must evaluate the data sets they use and carefully consider who may be rendered invisible by sampling practices or survey questionnaire design. </p>
<p>There is a need to design survey instruments that assess all aspects of reproduction – from high fertility to voluntary childlessness – and is inclusive of all marginalised groups and family formations.</p><img src="https://counter.theconversation.com/content/87047/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Some social groups are falling through the gaps of fertility data. Men, ethnic minorities and the LGBT community have explicitly been excluded from surveys.Liberty Barnes, Medical Sociologist, University of OregonJasmine Fledderjohann, Lecturer in Sociology and Social Work, Lancaster UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/720632017-02-28T11:09:58Z2017-02-28T11:09:58ZWhy men need to think about their fertility too<figure><img src="https://images.theconversation.com/files/157927/original/image-20170222-6413-1tbxvbz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Still got it.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/new-york-nov-15-2016-ronnie-563731321">Shutterstock</a></span></figcaption></figure><p>You are what you eat, so the saying goes. And it goes without saying that a lifetime of poor diet, minimal exercise and smoking increases your chance of getting obesity, heart disease and type 2 diabetes. About two-thirds of all deaths worldwide <a href="http://www.who.int/mediacentre/news/releases/2011/ncds_20110427/en/">are caused</a> by such diseases. It seems, then, that we are a product of our own modern lifestyles. But research is beginning to reshape our understanding of how our health as an adult can be affected by events much earlier in our lives. It might actually now be more accurate to say that “we are what our parents ate”. </p>
<p>And while we often hear about the importance of eating well, being a good weight and having the right nutrients are in women who want to have a baby – less is said about how much these things also affect a man who is passing on his genes. </p>
<p>More than 30 years ago, David Barker and colleagues <a href="http://www.sciencedirect.com/science/article/pii/S0140673686913401?via%3Dihub">found that</a> children who were small at birth were more likely to develop heart disease and type 2 diabetes as adults. From these observations, the Developmental Origins of Health and Disease (DOHaD) concept was established. Since then, hundreds of studies have <a href="http://physrev.physiology.org/content/85/2/571.long">strengthened the link</a> between maternal diet during pregnancy, the growth of her unborn offspring and their health as they grow into adults. However, the role that a father’s diet may play in directing the growth and health of his offspring has been largely ignored. </p>
<h2>Fertilising issues</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/158094/original/image-20170223-24090-14api0r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/158094/original/image-20170223-24090-14api0r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/158094/original/image-20170223-24090-14api0r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/158094/original/image-20170223-24090-14api0r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/158094/original/image-20170223-24090-14api0r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/158094/original/image-20170223-24090-14api0r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/158094/original/image-20170223-24090-14api0r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mice and rice.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/533353666?src=NptCDet8PG3AW18GAEG0Cg-1-73&size=medium_jpg">Shutterstock</a></span>
</figcaption>
</figure>
<p>While male fertility <a href="http://www.independent.co.uk/news/science/scientists-warn-of-sperm-count-crisis-8382449.html">has been declining</a> over recent decades, waistlines <a href="http://www.nhs.uk/Livewell/loseweight/Pages/statistics-and-causes-of-the-obesity-epidemic-in-the-UK.aspx">have been increasing</a>. The link between high BMI and poor sperm quality is actually well established. In both men and mice, obesity decreases production of testosterone while increasing the production of abnormal sperm – sperm with damaged DNA and sperm with poor motility. Sperm from obese and overweight men are also less likely to fertilise the egg, promote the embryo to develop and less likely to result in the birth of a child. </p>
<p>However, animal studies demonstrate that the negative effects of male obesity can be reversed, <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0071459">simply through exercise</a>. Other lifestyle factors including smoking, alcohol consumption and exposure to certain chemicals such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3074428/">phytoestrogens</a> (plant-based oestrogens) or drugs can also affect sperm quantity and quality. </p>
<h2>Passing it on</h2>
<p>We are now beginning to understand that a father’s poor diet can also affect the health of his adult offspring. <a href="http://www.nature.com/ejhg/journal/v14/n2/full/5201538a.html">One study</a> found links between a grandfather’s diet during his teenage years and the risk of his grandson dying from cardiovascular disease in adulthood. Interestingly, no such link was seen between grandfathers and granddaughters, suggesting the effects were passed only down the male line. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/158097/original/image-20170223-24079-1wuikzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/158097/original/image-20170223-24079-1wuikzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=519&fit=crop&dpr=1 600w, https://images.theconversation.com/files/158097/original/image-20170223-24079-1wuikzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=519&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/158097/original/image-20170223-24079-1wuikzn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=519&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/158097/original/image-20170223-24079-1wuikzn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=652&fit=crop&dpr=1 754w, https://images.theconversation.com/files/158097/original/image-20170223-24079-1wuikzn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=652&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/158097/original/image-20170223-24079-1wuikzn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=652&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Normal and abnormal sperm.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/spermogram-semen-parameters-teratozoospermia-normal-abnormal-350909255?src=aqvp7kIgjeFnhxnlYnD68w-3-90">Shutterstock</a></span>
</figcaption>
</figure>
<p>Data obtained from animal studies is also helping to highlight the importance of a father’s diet for his offspring. In these studies, researchers can manipulate food intake very precisely, only changing a single aspect of the diet. Studies <a href="http://www.publish.csiro.au/RD/RD13290">have looked at</a> the effects of diets high in fat or sugar, low in protein or what might happen even by simply reducing the total amount the male mouse eats. In response to all these poor and imbalanced paternal diets, their adult offspring become overweight and have poor cardiovascular and metabolic health. Other studies <a href="http://www.nature.com/articles/srep27010">have shown</a> that feeding male mice vitamins and antioxidants can prevent their offspring from having poor health in adulthood. </p>
<h2>Daddy fool?</h2>
<p>One additional interesting question that is still unanswered is whether paternal age is a factor for the health of his offspring. Many studies report that sperm production <a href="https://linkinghub.elsevier.com/retrieve/pii/S0015-0282(16)63090-X">declines with age</a> and that their motility declines also. As men age, so too do the stem cells within their testes that produce the sperm. Therefore, sperm from older men can have higher levels of damaged DNA in them, affecting the development of the embryo after fertilisation. Some studies also report links between paternal age and higher rates of autism, schizophrenia and some forms of cancer <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3854059/">in resulting children</a>. However, there are just too few studies to state definitively the effects of paternal age on the health of resulting children and what the underlying causes are. </p>
<p>But it now seems clear that the health of a father can affect the development and well-being of his offspring. Poor paternal health can even affect the chances of a man becoming a parent. </p>
<p>The idea that our adult health is determined before birth is of great interest, especially for those who want to either point the finger or absolve people of behaviour they see as undesirable. However, care and caution is always needed when interpreting results and drawing conclusions from animal and human retrospective studies. </p>
<p>It is still too early to advocate specific diets or nutrients that will promote sperm production and child health for all intending parents. Saying that, couples wishing to become parents could do a lot worse than assessing their current lifestyles habits (diet, smoking, drinking) to see if any improvements could be made.</p><img src="https://counter.theconversation.com/content/72063/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Watkins does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Thinking of having a baby? It’s not all down to women to get healthy in preparation.Adam Watkins, Assistant Professor, University of NottinghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/706362016-12-20T20:15:26Z2016-12-20T20:15:26ZWhy you can’t fry eggs (or testicles) with a cellphone<figure><img src="https://images.theconversation.com/files/151083/original/image-20161220-26741-nmhzbw.jpg?ixlib=rb-1.1.0&rect=721%2C0%2C3197%2C1982&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Pocket your phone without worry.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic.mhtml?id=533966416">Phone image via www.shutterstock.com.</a></span></figcaption></figure><p>A minor craze in men’s underwear fashions these days seems to be <a href="http://www.nbcnews.com/news/world/boxer-shorts-claim-protect-testicles-cellphone-radiation-n538576">briefs that shield the genitals</a> from cellphone radiation. The sales claim is that these products protect the testicles from the harmful effects of the radio waves emitted by cellphones, and therefore help maintain a robust sperm count and high fertility. These undergarments may shield the testicles from radiation, but do <a href="http://www.newsweek.com/boxer-rebellion-pocketed-cellphone-may-be-behind-your-infertility-287075">male cellphone users really risk infertility</a>?</p>
<p>The notion that electromagnetic radiation in the radio frequency range can cause male sterility, either temporary or permanent, has been around for a long time. As I describe in my book <a href="http://press.princeton.edu/titles/10691.html">“Strange Glow: The Story of Radiation</a>,” during World War II some enlisted men would consistently and inexplicably volunteer for radar duty just prior to their scheduled leave days. It turned out that a rumor had been circulating that exposure to radio waves from the radar equipment produced temporary sterility, which the soldiers saw as an employment benefit.</p>
<p>The military wanted to know whether there was any substance to the sterility rumor. So they asked <a href="https://www.nobelprize.org/nobel_prizes/medicine/laureates/1946/muller-bio.html">Hermann Muller</a> – a geneticist who <a href="https://www.nobelprize.org/nobel_prizes/medicine/laureates/1946/muller-lecture.html">won the Nobel Prize</a> for showing that x-rays could cause sterility and genetic mutations – to evaluate the effects of radio waves in the same fruit fly experimental model he had used to show that x-rays impaired reproduction. </p>
<p>Muller could find no dose of radio waves that produced either sterility or genetic mutations, and concluded that radio waves did not present the same threat to fertility that x-rays did. Radio waves were different. But why? Aren’t both x-rays and radio waves <a href="http://www.livescience.com/38169-electromagnetism.html">electromagnetic radiation</a>?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=326&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=326&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=326&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=410&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=410&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151022/original/image-20161220-26741-1sutwex.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=410&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The electromagnetic spectrum, tiny wavelengths on the left, longer wavelengths on the right.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:EM_Spectrum_Properties_reflected.svg">Inductiveload</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Yes, they are – but they differ in one key factor: They have very different wavelengths. All electromagnetic radiation travels through space as invisible waves of energy. And it’s the specific wavelength of the radiation that determines all of its effects, both physical and biological. The shorter wavelengths carry higher amounts of energy than the longer wavelengths.</p>
<p>X-rays are able to damage cells and tissues precisely because their wavelengths are extremely short – one-millionth the width of a human hair – and thus are highly energetic and very harmful to cells. Radio waves, in contrast, carry little energy because their wavelengths are very long – about the length of a football field. Such long-wavelength radiations have really low energies – too low to damage cells. And it’s this big difference between the wavelengths of x-rays and radio waves that the infertility theorists fail to recognize.</p>
<p>X-rays, and other high-energy waves, produce sterility by killing off the testicular cells that make sperm – the “<a href="https://www.repropedia.org/spermatogonium">spermatogonia</a>.” And x-ray doses must be extremely high to kill enough cells to produce sterility. Still, even when the doses are high, the sterility effect is usually temporary because the surviving spermatogonia are able to <a href="http://doi.org/10.1002/aja.1001180211">spawn replacements</a> for their dead comrades, and sperm counts typically return to their normal levels within a few months.</p>
<p>So, if high doses of highly energetic x-rays are needed to kill enough cells to produce sterility, how can low doses of radio waves with energies too low to kill cells do it? Good question.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/axUBeF-W7II?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Don’t fall for the phone-cooking-egg hoax.</span></figcaption>
</figure>
<p>At this point you may be thinking that you’ve seen videos of <a href="https://www.youtube.com/watch?v=axUBeF-W7II">cellphones cooking eggs</a>. And you’ve even experienced your cellphone getting pretty warm when it’s used heavily. But this doesn’t show that cellphones put out a lot of radiation energy. The cooked egg video is a prank, and the phone gets hot because of the heat generated by the chemical reactions going on within the battery, not from radio waves.</p>
<p>Still you protest: What about those sporadic reports claiming that cellphones suppress sperm counts? For the moment, that’s all they are – sporadic reports, unconfirmed by other investigators. You can find all kinds of random assertions about the effects of radiation on health, both <a href="http://www.orau.org/ptp/collection/quackcures/quackcures.htm">good</a> and <a href="https://www.scribd.com/document/59721111/TOP10-Myths-About-Radiation">bad</a>, most of which imply that there is some type of validated scientific evidence to support the claim. Why not believe all of them?</p>
<p>If we’ve learned anything over the years about scientific evidence, it’s that isolated findings from individual labs, reporting limited experimental data, do not a strong case make. Most of the very limited “scientific” reports of infertility caused by cellphones, often <a href="http://www.ewg.org/cell-phone-radiation-damages-sperm-studies-find">cited by anti-cellphone activists</a>, come from outside the radiation biology community, and are published in lower-tier journals of questionable quality. Few, if any, of these reports make any attempt at actually measuring the radiation doses received from the cellphones (probably because they lack either the expertise or the equipment required to do it).</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=384&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=384&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=384&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=483&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=483&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151040/original/image-20161220-26748-1ive95i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=483&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Human sperm, unconcerned by what’s in your pocket.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Sperm_(265_33)_human.jpg">Doc. RNDr. Josef Reischig, CSc.</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>And none actually measure fertility rates – the health endpoint of concern – but rather measure sperm counts and other sperm quality parameters and then infer that there will be an impact on fertility. In fact, sperm counts can vary widely between normally fertile individuals and even within the same individual from day to day. For example, men who frequently ejaculate have lower sperm counts, as you might expect, because they are regularly jettisoning sperm. (Men who ejaculate daily can have <a href="http://doi.org/10.1186/s12958-015-0045-9">sperm counts 50 percent lower</a> than men who don’t.) Perhaps the allegedly lower sperm counts of cellphone users just means that they are having more sex!</p>
<p>But seriously, the point is this: There are so many things that can affect sperm counts in big ways that minor fluctuations in sperm counts have no practical impact on whether a man will produce babies, even if it were true that cellphones can modestly suppress sperm counts.</p>
<p>It is clear that these infertility claims are not the consensus of the mainstream scientific community – a community that demands more rigorous evidence. There are many excellent laboratories around the world that study radiation effects, and it isn’t difficult to study infertility in fruit flies, mice and even people. (It’s fairly easy to find men willing to <a href="https://verdict.justia.com/2012/01/24/men-who-give-it-away">donate sperm samples</a>.) If the sterility story were true, there would be a chorus of well-respected laboratories from around the world singing the cellphone infertility song, not just a few.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=666&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=666&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=666&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=837&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=837&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151036/original/image-20161220-26748-eadyou.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=837&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Guglielmo Marconi, inventor of the radio.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/smithsonian/2551824648">Smithsonian Institution</a></span>
</figcaption>
</figure>
<p>The fact is, the current data suggesting that cellphones cause infertility are too weak to challenge the dogma of over 100 years of commercial experience with radio waves. Radio waves are not unique to cellphones. They have been used for telecommunication ever since <a href="http://www.history.com/this-day-in-history/marconi-sends-first-atlantic-wireless-transmission">Marconi first demonstrated in 1901</a> that they could carry messages across the entire Atlantic Ocean. Early radio workers received massive doses of radio waves, yet there is no indication they had any problems with their fertility. If they didn’t experience fertility problems with their high doses, how can the relatively low doses from cellphones have such an effect? Hard to understand.</p>
<p>Nevertheless, people can spend their money as they please and wear any underwear they want. But if you are still concerned about radio waves affecting your fertility, why not just carry your cellphone in your shirt pocket rather than your pants, and let your testicles be?</p><img src="https://counter.theconversation.com/content/70636/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Timothy J. Jorgensen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Did your holiday gift list include radiation-shielding undies to protect your privates from cellphone radio waves? A radiation expert explains they’re unnecessary – your phone won’t affect your fertility.Timothy J. Jorgensen, Director of the Health Physics and Radiation Protection Graduate Program and Associate Professor of Radiation Medicine, Georgetown UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/684192016-11-28T03:23:17Z2016-11-28T03:23:17ZHealth Check: why men wake up with erections<figure><img src="https://images.theconversation.com/files/146942/original/image-20161122-24550-1gkhp4s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many men are not actually aroused when they wake up erect. </span> <span class="attribution"><span class="source">from www.shutterstock.com.au</span></span></figcaption></figure><p>The morning penile erection, or as it is medically known, “nocturnal penile tumescence”, is not only an interesting physiological phenomenon, it can also tell us a lot about a patient’s sexual function.</p>
<p>Morning penile erections affect all males, even <a href="https://www.ncbi.nlm.nih.gov/pubmed/2192091">males in the womb</a> and male children. It also has a female counterpart in the less frequently discussed nocturnal clitoral erection.</p>
<h2>What causes erections?</h2>
<p>Penile erections occur in response to complex effects of the nervous system and endocrine system (the glands that secrete hormones into our system) on the blood vessels of the penis. </p>
<p>When sexually aroused, a message starts in the brain, sending chemical messages to the nerves that supply the blood vessels of the penis, allowing blood to flow into the penis. The blood is trapped in the muscles of the penis, which makes the penis expand, resulting in an erection. </p>
<p>Several hormones are involved in influencing the brain’s response, such as testosterone (the main male hormone).</p>
<p>This same mechanism can occur without the involvement of the brain, in an uncontrolled reflex action that is in the spinal cord. This explains why people with spinal cord damage can still get erections and why you can get erections when not sexually aroused.</p>
<h2>What about erections while we sleep?</h2>
<p>Nocturnal penile erections occur during Rapid Eye Movement (REM) sleep (the phase during which we dream). They occur when <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1351051/">certain areas of the brain</a> are activated. This includes areas in the brain responsible for stimulating the parasympathetic nerves (“rest and digest” nerves), suppressing the sympathetic nerves (“flight and fight” nerves) and dampening areas <a href="https://faculty.washington.edu/chudler/auto.html">producing serotonin</a> (the mood hormone).</p>
<p>Sleep is made up of several cycles of REM and non-REM (deep) sleep. During REM sleep, there is a shift in the dominant system that’s activated. We move from sympathetic (fight and flight) stimulation to parasympathetic (rest and digest) stimulation. This is not found during other parts of the sleep cycle. </p>
<p>This shift in balance drives the parasympathetic nerve response that results in the erection. This is spontaneous and does not require being awake. Some men may experience nocturnal penile tumescence during non-REM sleep as well, particularly older men. The reason for this is unclear.</p>
<p>The reason men wake up with an erection may be related to the fact we often wake up coming out of REM sleep.</p>
<p>Testosterone, which is at its highest level in the morning, has also been shown to enhance the frequency of nocturnal erections. Interestingly, testosterone has <a href="https://www.ncbi.nlm.nih.gov/pubmed/8848520">not been found to greatly impact</a> visual erotic stimuli or fantasy-induced erections. These are predominantly driven by the “reward system” of the brain which secretes dopamine.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/147520/original/image-20161125-15325-3s9i7p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/147520/original/image-20161125-15325-3s9i7p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/147520/original/image-20161125-15325-3s9i7p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/147520/original/image-20161125-15325-3s9i7p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/147520/original/image-20161125-15325-3s9i7p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/147520/original/image-20161125-15325-3s9i7p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/147520/original/image-20161125-15325-3s9i7p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/147520/original/image-20161125-15325-3s9i7p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Men don’t wake up with erections because they’ve been having sexy dreams.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p>Since there are several sleep cycles per night, men can have as many as five erections per night and these can last up to 20 or 30 minutes. But this is very dependent on sleep quality and so they may not occur daily. The number and quality of erections declines gradually with age but they are often present well beyond “retirement age” - attesting to the sexual well-being of older men.</p>
<p>It’s also important to highlight the counterpart phenomenon in women, which is much less researched. Pulses of blood flow in the vagina during REM sleep. The <a href="http://www.tandfonline.com/doi/abs/10.1080/00926237908403713">clitoris engorges</a> and vaginal sensitivity increases along with vaginal fluidity.</p>
<h2>What’s its purpose?</h2>
<p>It has been suggested “pitching a tent” may be a mechanism for alerting men of their full overnight bladder, as it often disappears after emptying the bladder in the morning. </p>
<p>It’s more likely the reason for the morning erection is that the unconscious sensation of the full bladder stimulates nerves that go to the spine and these respond directly by generating an erection (a spinal reflex). This may explain why the erection goes away after emptying one’s bladder.</p>
<p><a href="https://www.sciencedaily.com/releases/2008/07/080702091346.htm">Scientific studies</a> are undecided as to whether morning erections contribute to penile health. Increased oxygen in the penis at night may be beneficial for the health of the muscle tissues that make up the penis.</p>
<h2>What does it mean if you don’t get one?</h2>
<p>Loss of nocturnal erection can be a useful marker of common diseases affecting erectile function. One example is in <a href="http://psycnet.apa.org/psycinfo/1978-32025-001">diabetics</a> where the lack of morning erections may be associated with erectile dysfunction due to poor nerve or blood supply to the penis. In this case, there’s a poor response to the messages sent from the brain during sleep which generate nocturnal erections. </p>
<p>It is thought nocturnal erections can be used as a marker of an anatomical ability to get an erection (a sign that the essential body bits are working), as it was thought to be independent of psychological factors that affect erections while awake. <a href="http://www.sciencedirect.com/science/article/pii/0006322388901199">Studies have suggested</a>, however, that mental health disorders such as severe depression can affect nocturnal erections. Thus its absence is <a href="http://jamanetwork.com/journals/jamapsychiatry/article-abstract/492087">not necessarily a marker</a> of disease or low testosterone levels.</p>
<p>The frequency of morning erections and erection quality <a href="http://www.sciencedirect.com/science/article/pii/S0090429500008414">has also been shown to</a> increase slightly in men taking medications for erectile dysfunction such as Viagra.</p>
<h2>So is all this morning action good news?</h2>
<p>While some men will put their nocturnal erections to good use, many men are not aroused when they have them and tummy sleepers might find them a nuisance.</p>
<p>Since good heart health is associated with an ability to have erections, the presence of nocturnal erections is generally accepted to be good news. Maintaining a healthy lifestyle is important in <a href="https://www.ncbi.nlm.nih.gov/pubmed/22072232">avoiding and even reversing</a> erectile dysfunction, so it’s important to remember to eat healthily, maintain a healthy weight, exercise and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4291878/">avoid smoking and alcohol</a>.</p><img src="https://counter.theconversation.com/content/68419/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sergio Diez Alvarez does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Morning penile erections affect all males, even males in the womb and male children.Sergio Diez Alvarez, Director Of Medicine, The Maitland and Kurri Kurri Hospital, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/439342015-06-26T14:44:02Z2015-06-26T14:44:02ZUniversal sperm bank would strike at a core human freedom<figure><img src="https://images.theconversation.com/files/86544/original/image-20150626-1431-19ziidt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Humanity on ice</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>A world in which the state coordinates the conception of almost every child comes straight from the pages of dystopian science fiction. And yet that was the implication of a <a href="http://www.bbc.co.uk/news/health-33253278">recent suggestion</a> that the NHS ought to freeze the sperm of all 18-year-old males to counter the effects of the increasing age at which men become fathers.</p>
<p>Writing in the Journal of Medical Ethics, Dr Kevin Smith of Abertay University <a href="jme.bmj.com/content/early/2015/06/02/medethics-2014-102405.short">points out</a> that children of older fathers have an increased risk of certain medical conditions such as autism, bipolar disorder, obesity and schizophrenia. This means, he argues, we should enable older men to use their younger sperm to father children by creating a universal sperm bank.</p>
<p>Smith claims this idea is “ethically unproblematic”. But there are, I think, a number of concerns he simply fails to consider. Given Smith is a <a href="http://www.abertay.ac.uk/research/staff/k_smith/">self-avowed utilitarian</a> he should, at least, consider if the harms supposedly eliminated by his proposal will not simply be replaced by another set of ethically relevant burdens. Unfortunately a number of important concerns are absent from his discussion.</p>
<p>For example, the proposal implies that artificial insemination would become “<a href="jme.bmj.com/content/early/2015/06/02/medethics-2014-102405.short">the norm for procreation</a>”. This would mean those women who want to reproduce with an older male would, at minimum, have to undergo a relatively risk-free but somewhat unpleasant medical procedure – artificial insemination – in order to become pregnant. Others would have to endure the greater risks, and discomfort, of <em>in vitro</em> fertilisation (IVF).</p>
<h2>Human error</h2>
<p>Given that no human-designed and operated system is ever entirely free from error, there will always be the possibility of a mistake. Sperm might be labelled wrongly, it might be kept in sub-optimal conditions, or it might be accidentally destroyed. If it becomes the norm for young men to bank their sperm, they may also become more inclined towards vasectomy as a form of contraception. This might mean an increase in sexually transmitted infections. Taken together, these effects could leave some men unable to procreate.</p>
<p>This system would also mean the state would essentially control a genetic database that covered virtually the entire population, something that would create a number of other ethical issues. As we have seen in <a href="http://www.theguardian.com/society/2014/mar/06/widow-high-court-fight-dead-husband-sperm">recent court battles</a> involving wives wishing to access their husband’s frozen sperm, preserving fertility in this way raises the questions of <a href="http://www.theguardian.com/commentisfree/2014/mar/07/widow-husband-sperm-victory-conceiving-parent">who has the right</a> to access that genetic material, and <a href="http://www.theguardian.com/law/2012/sep/11/marital-assets-sperm">under what conditions</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/86547/original/image-20150626-1438-oj7os3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86547/original/image-20150626-1438-oj7os3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86547/original/image-20150626-1438-oj7os3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86547/original/image-20150626-1438-oj7os3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86547/original/image-20150626-1438-oj7os3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86547/original/image-20150626-1438-oj7os3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86547/original/image-20150626-1438-oj7os3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">No, you can’t have your sperm back.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>It also raises questions about the state’s responsibly for the well-being of any offspring. Should the state allow men to access their banked sperm <a href="http://www.theguardian.com/world/2015/may/23/annegret-raunigk-german-woman-birth-quadruplets-aged-65">regardless of their age</a>, or should there be a cut-off point? If the latter, would that not undercut the very purpose of such banks, as some of these older men may well successfully reproduce the old-fashioned way?</p>
<p>Socially stigmatising later-life reproduction, as Smith’s article seems to advocate, seems ethically disconcerting at best. But it also seems at odds with the cited aims of his proposals to enable older parenthood. How is one meant to distinguish between a child conceived artificially using the sperm of a young man and one conceived through the sexual activities of an older man and his partner? </p>
<h1>Eroding freedom</h1>
<p>The other issue created by widespread state responsibility for artificial conception is that of our procreative freedom. At present, most of us have a large degree of reproductive autonomy. With two fertile individuals of the opposite sex, human procreation can proceed without interference. Currently, the state essentially licenses adoptive parents, and <a href="https://books.google.co.uk/books?hl=en&lr=&id=GbETBAAAQBAJ&oi=fnd&pg=PA151&dq=adoption+reproduction+parent+license&ots=qc8HuBIXE9&sig=VtaLbh8nMJH1Rj1wBNq1VNtWn1k#v=onepage&q=adoption%20reproduction%20parent%20license&f=false">some have argued</a> that the kind of conditions they have to meet <a href="https://books.google.co.uk/books?id=NgXaAAAAMAAJ&q=Should+Parents+Be+Licensed?&dq=Should+Parents+Be+Licensed?&hl=en&sa=X&ei=UoqMVaPaAdapyASW2YOgCw&ved=0CCEQ6AEwAA">should be</a> <a href="http://www.jstor.org/stable/2265111?seq=1#page_scan_tab_contents">demanded of</a> parents <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1468-5930.2010.00497.x/abstract">more generally</a>. But most people would consider the state taking action to prevent individuals reproducing to be a moral travesty. </p>
<p>But the routine use of a universal state sperm bank would inevitably raise questions that could lead to just that. Should banked sperm be provided to a man who already has a number of children? What if he has multiple children with different women? Should there be an interval – and how long – between providing a man’s sperm to conceive with one woman and then again with another? How long must a man and woman know each other before the state administered sperm bank will provide them with artificial insemination services? Must a man be in a relationship with his procreative partner? If so, what sort of relationship must that be? How should sperm banks deal <a href="http://www.theguardian.com/lifeandstyle/2012/apr/06/couples-in-open-relationships">with open</a> or <a href="http://www.theguardian.com/lifeandstyle/2006/jul/09/familyandrelationships2">polyamorous relationships</a>? Indeed, how should it deal with adulterous relationships? If a man wants to conceive with two women, must the state sperm bank ensure they know about each other and consent to the reproductive choices being made? </p>
<p>These questions cannot easily be accommodated by the supposedly non-judgmental stance inhabited by contemporary medical professionals. Contrary to what Smith claims, universal sperm banking would face fundamental challenges at both a practical and ethical level. A responsible bioethicist who purports to offer an ethical solution to what is, in fact, a relatively ill-defined biomedical concern, cannot simply ignore them. Unfortunately, that seems to be precisely what Smith has done.</p><img src="https://counter.theconversation.com/content/43934/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nathan Emmerich does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Freezing young men’s sperm might remove worries about them fathering children in later life, but do we really want the state routinely meddling in conception?Nathan Emmerich, Visting Research Fellow, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/437532015-06-26T05:11:56Z2015-06-26T05:11:56ZForget freezing sperm, it’s time for men to take responsibility for the foreplay of fatherhood<figure><img src="https://images.theconversation.com/files/86423/original/image-20150625-29083-wfb01d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">'I did it, darling!'</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>The right of a woman to control her fertility is at the very heart of feminist politics. It’s a cornerstone for women’s ability to secure economic freedom through the labour market rather than the man market, by determining when she should have a baby.</p>
<p>Feminism, especially in its second wave since the 1970s, has been central to producing these changes. For example, in the early part of the 20th century, contraceptive practices were rooted in men’s culture and it was men who initiated discussions of birth control, <a href="https://books.google.co.uk/books?hl=en&lr=&id=PHZYajzK3JcC&oi=fnd&pg=PP8&ots=FG8dGyTto_&sig=GLWBhnAKYCeYhmkhESFVSt-pOlY#v=onepage&q&f=false">determining the choice</a> of methods and interacting with providers.</p>
<p>For women with economic resources in high-income countries across the world, this is largely no longer the case. Just last week, the European Medicines Agency licensed a change in the <a href="http://www.telegraph.co.uk/news/health/news/9618015/Five-day-after-pill-to-be-sold-at-chemists-without-prescription.html">availability of EllaOne</a>. Now, women of any age can obtain this “morning-after pill” over the counter in pharmacies following a consultation with the pharmacist. In addition, in the UK at least, contraception is free of charge to all women from 13 years of age with a prescription from a family physician or practice nurse.</p>
<p>The results of this feminist movement have been immense in terms of advancing control for women over when, and with whom, they become pregnant. But with all these rights, of course, come all the responsibilities. There was no talk last week of making EllaOne or other such emergency contraception available to men. If a man walked into a pharmacy and requested EllaOne, would he be regarded as being a loving partner or a coercive one?</p>
<p>This problem raises the question of how men participate in family planning as well as heat-of-the-moment decision making. Why is it that women’s bodies bear the responsibility of birth control? Why don’t we have a range of contraception available for men other than the male condom or male vasectomy? Men are assumed to be sexually active but reproductively innocent. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/86429/original/image-20150625-29087-1120ev8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86429/original/image-20150625-29087-1120ev8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86429/original/image-20150625-29087-1120ev8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86429/original/image-20150625-29087-1120ev8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86429/original/image-20150625-29087-1120ev8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86429/original/image-20150625-29087-1120ev8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86429/original/image-20150625-29087-1120ev8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Men: don’t be lazy.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>The same issue applies to fertility. We often hear stories of a <a href="http://www.wsj.com/articles/SB10001424053111903461104576458134196248312">fertility crisis</a> in relation to women <a href="http://www.dailymail.co.uk/health/article-2805763/Ten-times-harder-pregnant-aged-43-37-Doctors-warn-speeding-biological-clock-means-women-four-years-conceive-four-months.html">delaying childhood</a> in order to have both career and babies, only to find assisted reproductive technologies are <a href="http://www.theguardian.com/lifeandstyle/2010/jul/03/ivf-fertility-infertility-gedis-grudzinskas">not always successful</a>. Where are all the men in these stories?</p>
<p>A growing <a href="http://www.rbej.com/content/13/1/35">body of evidence</a> suggests that men’s bodies are also implicated in this fertility crisis, highlighting that sperm quality reduces with increasing paternal age from 40 years on. However, society, science and healthcare are focused on women’s maternal bodies. According to <a href="http://www.telegraph.co.uk/news/health/11676806/Eating-fruit-and-vegetables-can-boost-fertility-but-men-rarely-take-the-advice.html">one researcher</a>: “It’s always the wife who prompts the investigation. Men are lazier and are keen to rely on the women.”</p>
<p>Notwithstanding advances of techniques that rely on medically <a href="http://www.uhcw.nhs.uk/ivf/treatments/ssr">removing sperm</a> from men’s testicles, most invasive fertility treatments are practised on women’s bodies. This is even the case when fertility problems rest with the male partner and methods are used to help make the woman’s body more receptive to faulty sperm.</p>
<p>The suggestion that men should be offered the option of <a href="http://www.bbc.co.uk/news/health-33253278">freezing their sperm</a> at 18 through the NHS is another way of offering men the opportunity to kick this topic into touch. Why not instead help boys and men to think through the potential of fatherhood in their lives, to plan it alongside their work lives as women do? Why not make fatherhood a routine part of relationship and sex education in schools – and encourage boys, as well as girls, to have conversations about when and how they might become a parent? It’s time to engage boys and men in the foreplay of fatherhood.</p>
<p>Fatherhood has recently received increased positive attention in society. But there is also a need to engage men productively so they have opportunities to think and plan for parenthood alongside their reproductive partners and receive appropriate counselling and medical treatment.</p><img src="https://counter.theconversation.com/content/43753/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Maria Lohan has received research funding from the Economic and Social Research Institute; the National Institute for Health Research; the Health Services Executive of Ireland & the Department of Health and Public Health Agency of Northern Ireland. She is affiliated with the Men's Health Forum of Ireland MHFI, a not for profit organisation to improve men's health.</span></em></p>Fertility, as with contraception, is seen as a woman’s issue, but the science shows this needs to change.Maria Lohan, Senior Lecturer in Nursing and Midwifery, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/437522015-06-25T16:04:28Z2015-06-25T16:04:28ZDeclining sperm quality in older men puts the issue at the centre of fertility debate<figure><img src="https://images.theconversation.com/files/86392/original/image-20150625-13016-11w8ruf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">"Mummy says you should have gotten a move on."</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>We tend to think of women’s declining fertility as being the reason older couples can struggle to conceive. But, in fact, the <a href="http://www.bbc.co.uk/news/health-21197679">growing number</a> of men putting off fatherhood until later in life may find there are big consequences for them and their kids – or lack of them.</p>
<p>One scientist, Dr Kevin Smith of Abertay University in Dundee, has even gone so far as to call for the NHS to <a href="http://www.bbc.co.uk/news/health-33253278">start freezing</a> the sperm of all 18-year-old men in the UK. He argues this could enable the men to have children later in life without some of the risks associated with doing so.</p>
<p>The “right time” to become a parent is less clear biologically for men than for women. Men don’t go through an equivalent to the menopause. But this may have lured us into a false sense that fatherhood is just as natural at 70 as at 20 years old. </p>
<p>The social acceptability of older fatherhood has been reinforced by celebrities such as <a href="http://www.telegraph.co.uk/news/uknews/4371034/Paul-McCartney-says-he-loves-fatherhood-at-66.html">Paul McCartney</a>, <a href="http://www.telegraph.co.uk/news/celebritynews/7935821/Rod-Stewart-to-be-a-father-at-66-celebrities-who-became-dads-in-their-autumn-years.html">Rod Stewart</a> and <a href="http://www.dailymail.co.uk/tvshowbiz/article-2277922/Steve-Martin-father-time-age-67.html">Steve Martin</a> becoming dads again in their middle-to-old age. Society assumes that sperm from older men are just as healthy as those from young men. But the <a href="http://www.ncbi.nlm.nih.gov/pubmed/25926606">evidence suggests</a> this is a myth.</p>
<h1>Declining quality</h1>
<p>Most scientists agree that <a href="http://ehp.niehs.nih.gov/121-a46/">the quality</a>, if not <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2605.2005.00635.x/abstract">the quantity</a>, of sperm has decreased in the past 50 years. “Just 25% of European men have good-quality sperm” <a href="http://www.thetimes.co.uk/tto/health/news/article4473064.ece">we were told</a> by the University of Copenhagen’s Niels Jorgensen at a recent conference, where he reported his 70 years’ worth of data. This decline in quality, he said, can lead to longer times to natural conception, smaller families and as many as “15% of men [needing] to resort to fertility treatment to have a family”.</p>
<p>However, given that a man can produce up to 500m sperm in a single ejaculate, the winning sperm is likely to be among that man’s best, whether successful in spontaneous conception or with fertility treatment. So the risk of that particular sperm being of poor quality and causing problems with resulting children isn’t likely to be significantly affected by declining overall quality. The <a href="http://www.pm360online.com/eshre-art-does-not-hurt-academic-performance-in-teens/">latest reassuring evidence</a> suggests that artificially conceived children achieve equal academic performance and experience no increased risk of cancer compared to children conceived naturally. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/86414/original/image-20150625-13016-13ptqnt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86414/original/image-20150625-13016-13ptqnt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86414/original/image-20150625-13016-13ptqnt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86414/original/image-20150625-13016-13ptqnt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86414/original/image-20150625-13016-13ptqnt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86414/original/image-20150625-13016-13ptqnt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86414/original/image-20150625-13016-13ptqnt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">No time to wait.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Because this decline in the male population’s semen quality has been observed over such a short time interval, it may be caused by lifestyle, occupation and environment rather than by genetic anomalies. If so, we may be able to prevent any further impairment or even improve semen quality again (<a href="https://theconversation.com/are-plastics-making-men-infertile-43751">although it won’t be easy</a>). </p>
<p>However, the growing number of older fathers is more concerning. There is <a href="http://www.rbej.com/content/13/1/35">much evidence</a> that sperm quality falls as men get older, from around the age of 40. Unlike the problems with young men’s sperm quality, problems for older men are more likely to be genetic, less likely to be reversible and come with possible short and long-term effects on potential children.</p>
<h1>Men matter</h1>
<p>The impact of how men’s DNA changes over time on the health of any children they father is a much-neglected topic. Even in the 21st century, we tend to consider “mother and baby” health together and reduce the father to a single sperm of standard quality. This is tantamount to treating human reproduction as an asexual process where the mother effectively clones herself (parthenogenesis).</p>
<p>Over the past decade the rapid advances in molecular technology have shown that assumption to be incorrect. <a href="http://www.ncbi.nlm.nih.gov/pubmed/24194569">Numerous studies</a> report links between older fathers and increased risk of genetic diseases specifically associated with DNA mutations, abnormal numbers of chromosomes, and the effect of environmental (epigenetic) factors on genes. </p>
<p>Together, these <a href="http://www.ncbi.nlm.nih.gov/pubmed/25926606">robust studies</a> show associations between older fatherhood and greater rates of cancer, childhood mortality and mental disorders such as bipolar disease, autism and schizophrenia.</p>
<p>One <a href="http://archpsyc.jamanetwork.com/article.aspx?articleid=1814892">piece of research</a> suggests that children born to fathers older than 45 are more likely to die in childhood than the general population. <a href="http://www.ncbi.nlm.nih.gov/pubmed/24577047">Similar evidence</a>
was found showing a greater likelihood of suicide attempts, substance abuse problems and low educational attainment.</p>
<p>Smith has done this issue a great service by raising the perils of delayed fatherhood. While I do not believe the risks justify freezing the sperm of every 18-year-old in the country – nor do I think men would use this service – Smith’s suggestion has raised the profile of this problem a lot in just one day.</p>
<p>Is there an age when men are less “fit for fatherhood”? We certainly have sufficient evidence to suggest that healthy babies are more likely to be born to young men as well as young women. When it comes to parenthood, men need to “man up” sooner.</p>
<p><em>This article has been amended to state that Dr Kevin Smith works for Abertay University in Dundee, not Dundee University as previously stated.</em></p><img src="https://counter.theconversation.com/content/43752/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sheena Lewis receives funding from NIHR and EU. She is also CEO of a university spin out company , Lewis Fertility Testing Ltd </span></em></p>Calls to freeze every 18-year-old’s sperm might be drastic but men need to realise it’s a myth that there’s no limit to their fertility.Sheena Lewis, Professor of Reproductive Medicine, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/437512015-06-25T12:11:26Z2015-06-25T12:11:26ZAre plastics making men infertile?<figure><img src="https://images.theconversation.com/files/86368/original/image-20150625-12990-1pwdna7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Gird your loins</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p><a href="http://www.thetimes.co.uk/tto/health/news/article4473064.ece">Recent research</a> has reignited concerns that exposure to chemicals from plastics might be to blame for low sperm counts in young men. I share the concerns about the high prevalence of low sperm counts <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2605.2005.00635.x/abstract">(one in six young men)</a> – and <a href="http://embor.embopress.org/content/13/5/398.long">my research</a> is directed at trying to identify what causes it. But whether plastics are to blame isn’t a simple matter.</p>
<p>Plastics are part of the fabric of our everyday lives and perform many essential functions. Without their thousands of uses, many of which are not obvious to us, our modern world could not function as it is. Plastics bring everyday benefits whether through children’s toys, the insulation around electrical wiring, their utility in food containers/wraps or their widespread use in medical products from blood bags, gloves and syringes, to the coating of some tablets and capsules. </p>
<p>But are there hidden dangers of plastics to human health, especially to male fertility? This is a surprisingly difficult question to answer, not least because everyone is exposed to chemicals that derive from plastics. This means we don’t really have an unexposed group (“control”) against which to compare. </p>
<p>Most people probably don’t understand how we are exposed to chemicals from plastics. After all, we don’t eat the plastic wraps around food or chew electric wiring. Plasticisers are chemicals used to make plastic (which is naturally hard and brittle) bendy and resistant to breaking, so prolonging its useful life. As a guide, the more flexible the plastic, the more plasticiser it will contain. The most widely used plasticisers are called <a href="http://toxtown.nlm.nih.gov/text_version/chemicals.php?id=24">phthalates</a>, which come in different forms with different uses.</p>
<p>Plasticisers leach out of the plastic over time and will contaminate any food, drink or other material with which they have contact. This was the primary reason why phthalate plasticisers were removed from use in water bottles many years ago and replaced by polyethylene terephthalate, which has different properties. Nevertheless our main route of exposure to the most commonly used phthalate <a href="http://www.ncbi.nlm.nih.gov/pubmed/23333758">is still via</a> our food/diets, even if we do not fully understand how this contamination occurs.</p>
<p>What ignited concerns about phthalate effects on fertility were <a href="http://humrep.oxfordjournals.org/content/18/7/1383.long">studies in laboratory rats</a>. These showed that exposure in pregnancy to certain phthalates caused reproductive disorders in the male offspring, including reduced sperm counts and fertility. As pregnant women (and thus the male fetuses in their wombs) are exposed to the same phthalates, could this be the cause of reproductive disorders in men?</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/86379/original/image-20150625-13016-1u6t4cw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/86379/original/image-20150625-13016-1u6t4cw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/86379/original/image-20150625-13016-1u6t4cw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/86379/original/image-20150625-13016-1u6t4cw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/86379/original/image-20150625-13016-1u6t4cw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/86379/original/image-20150625-13016-1u6t4cw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/86379/original/image-20150625-13016-1u6t4cw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One is all you need.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Conflicting evidence</h2>
<p>The seemingly direct way to answer this question is to measure phthalate exposure of pregnant women and see if high exposure is associated with reproductive disorders in their sons. Some, but not all, <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1280349/">such studies</a> have shown an association between male reproductive disorders and phthalate exposure of the mother. The problem is that this approach can never prove that the exposure caused the disorder. More importantly, <a href="http://press.endocrine.org/doi/10.1210/jc.2011-2411?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed">other evidence</a> points in the completely <a href="http://www.greenbiz.com/news/2010/05/24/science-behind-phthalates-ban">opposite direction</a>.</p>
<p>Phthalates cause male reproductive disorders in rats by reducing production of the male sex hormone – testosterone – by the testes of the male fetus. To induce this effect, pregnant rats have to be exposed to phthalate levels 50,000 times higher than pregnant women are exposed to. Exposure of human fetal testes (obtained with ethical permission from legal pregnancy terminations) to the same high phthalate levels as in rats has no effect on their testosterone production. Nor do reproductive disorders occur in male monkeys after their mothers are exposed to equally high phthalate levels during pregnancy. </p>
<p>In research it is common to be faced with problems such as this, where different types of data simply do not agree. But what should we do in the face of this uncertainty? One reaction is to assume the worst, accept the association studies and ignore the studies that don’t agree with them. In which case, the next step would be to ban or restrict phthalate use, resulting in numerous changes to our modern society that will affect everyone. Some argue that this is the <a href="https://chemicalwatch.com/20622/us-panel-wants-five-phthalates-banned-in-childrens-products">safest route</a> to take.</p>
<p>While I am 100% in favour of safety, I know that in science one cannot simply choose to ignore evidence that does not fit a particular point of view, at least not when that evidence is known to be robust. It is not an evidence-led approach and is, by any standards, nonsensical.</p>
<p>This does not mean that I am fully convinced that plastics are 100% safe, but neither does the available evidence convince me that they are a major factor in male reproductive disorders. I am convinced that something in our environment or lifestyles is causing low sperm counts. I just wish I knew what.</p>
<p><em>Note: this piece was changed on August 6 2015 to be clear that there is no suggestion plastic drinking bottles still contain phthalate plasticisers.</em></p><img src="https://counter.theconversation.com/content/43751/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Sharpe receives funding from the UK Medical research Council.</span></em></p>Recent research into the health effects of the plastic-making chemicals phthalates has reignited concerns about low sperm counts. But the evidence is far from conclusive.Richard Sharpe, Group leader, male reproductive health, The University of EdinburghLicensed as Creative Commons – attribution, no derivatives.