Morning penile erections affect all males, even males in the womb and male children.
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?
Fertility, as with contraception, is seen as a woman's issue, but the science shows this needs to change.
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.
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.