Women are rarely given the chance to forget about our biological clocks: their starting, slowing, stopping. I remember talking about whether I’d want children with my mum when I was six or seven years old. Now that I’m 32, my friends are having children, debating having them, or dating in the hopes of having the option.

My female friends, that is. My impression of the men in my life is that they are not really thinking about children at all, instead assuming that they will happen “one day” or waiting for the decision to be made for them – by their partner, or circumstance. Their declining fertility – something that women are made keenly aware of from a young age – doesn’t seem to factor into it.

That is despite what has been described as an “urgent, global” crisis of sperm counts – or, more memorably, “spermageddon”. Average sperm counts worldwide have declined by half over the past 50 years, and more steeply still in the past 20. Various possible reasons for this have been floated, from environmental pollutants to inactive lifestyles and use of technology such as smartphones. But we still aren’t really sure what’s driving it, leading a consortium of international experts to call for action last year.

This is not a new problem, yet there persists a shocking disconnect. Despite these well-known threats to male fertility, the vast majority of the focus on infertility – by governments, health services and couples – falls on women. The male partner is solely responsible in about 20% of infertility cases, and is a contributing factor in a further 30% to 40%. Often, male and female infertility can coexist. Yet it’s overwhelmingly women who shoulder the burden of family planning, the social stigma of acting with urgency and the stress, even trauma, of infertility treatment.

Study of the causes and treatments for male infertility is chronically underfunded, being seen by research bodies as falling under the purview of the booming fertility industry – but its extensive R&D focuses on women. In roughly 25% of cases of heterosexual couples presenting with troubles conceiving, the man does not undergo any evaluation at all.

It shows how – to give the title of the paper where I found that disturbing fact – “male infertility is a women’s health issue”, under-researched by scientists, neglected by industry and largely ignored by men themselves.

It’s hard not to feel frustrated by the stricken response, common among men in their 30s and older, to a woman they’re dating or even love raising the subject of children. And it’s hard not to feel enraged by the number who are dating women 10 years their junior in the hopes (subconscious or not) of delaying the conversation.

In today’s shifty, commitment-phobic dating culture, I’ve found that even expressing that you don’t want children can put men off – not because they are certain that they do, but because they haven’t given it real thought and (to put it less charitably) want to keep their options open.

It’s not entirely men’s fault: unlike women, they have not been socialised under the spectre of their fertility “falling off a cliff” after a certain age. For many, the subject may only ever come up twice: first at school, in the context of learning how to prevent pregnancy and then, at a much later date, when it’s being posited as a real possibility.

But men’s complacency about their sperm quality, and their reticence to engage seriously with the question of whether they want children until it’s forced on them, are compounding women’s individual struggles, as well as fundamental inequities in our approach to family planning.

It also neglects the very real risk that – when the stars finally align for them to become fathers – that their swimmers won’t be as robust as they believe them to be. Yes, male fertility declines later than women’s, allowing them longer to consider the question, but no one is immune to the ravages of age.

Often, in trying to count the remaining time on our fertility clock, we point to examples of famous people having children into their 50s and beyond – but you are no more Mick Jagger than I am Rachel Weisz. Without knowing the truth about their “fertility journey”, celebrities’ late-in-life success stories should be taken as proof not of the timeframe we all have to work with, but their markedly larger resources.

It is heartening to see signs of increasing awareness of the crisis in male fertility, led by start-ups such as Jack Fertility and ExSeed (which offer at-home sperm-testing) and by men with personal experience, such as Ciaran Hannington and Shaun Greenaway, hosts of The Male Fertility Podcast. Since 2020, fertility and family planning have also been made part of secondary schools’ statutory sex education, with teaching aids recently co-developed by the British Fertility Society.

But it will take decades to undo the pernicious belief that family planning is a women’s issue, and perhaps longer for men to feel equally invested. In the meantime, here is what everyone should know, informed by my conversations with fertility experts:

Women’s fertility peaks at 20, and sees a marked decrease after the age of 35, when the risks associated with pregnancy and childbirth increase.

Men also experience reproductive ageing, with those over the age of 40 about half as fertile as those under 25. Drinking, smoking, unhealthy lifestyles, medication, exposure to heat and toxins, and steroid use can all hasten the decline.

Children born to older fathers, meanwhile, are at elevated risk of birth defects, health problems such as cancer, and mental health disorders such as schizophrenia and bipolar disorder.

“My main advice?” concludes family planning researcher Tanja Tydén. “If you know that you want to have children, don’t wait too long.”

Women may not need further reminders, but men might do well to remember: you can’t bury your head in the sand.

• Elle Hunt is a freelance journalist

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