In Margaret Atwood's dystopian 1985 novel The Handmaid's Tale – currently being dramatised on Channel 4 – it is forbidden to suggest that a man could possibly be sterile. Fertility, in totalitarian Gilead, is strictly a female concern.
In the real world, male-factor infertility accounts for about half of the one in six couples who have problems conceiving. But, until now, society has been slow to talk about it, and slower again to recognise what we now know to be true: men’s fertility, just like women’s, declines with age.
New research reported at the annual meeting of the European Society of Human Reproduction and Embryology in Geneva on Tuesday shows that fertility treatment is less likely to be successful for couples in which the male partner is older than 40.
Led by reproductive biologist Laura Dodge from Harvard University, the study – which has not yet been peer-reviewed – analysed 15 years' worth of IVF treatments carried out in Boston between 2000 and 2014 on almost 8,000 couples.
It found that women aged under 30 whose male partner was aged between 30 and 35 had a 73 percent chance of a live birth after IVF. But that success rate fell to 46 per cent when the man was aged 40 to 42. When the female partner was also aged 40 to 42, the age of the male partner had no impact on birth rate.
“Women aged 35–40 did significantly benefit from having a male partner who is under age 30, in that they see a nearly 30 percent relative improvement in cumulative incidence of live birth,” Dodge said.
The reason for the decline in fertility is thought to be sperm mutations and a declining sperm count.
This isn’t the first piece of scientific evidence to highlight potential downsides of delaying fatherhood. Previous studies have found that older fathers were more likely to have children with a range of psychiatric, social and educational problems.
A study in 2001 at Columbia University found that as many as one in four cases of schizophrenia are linked to advanced paternal age. Another Columbia University study, five years later, found there was a 60 per cent higher risk of miscarriage when the father was aged over 40, regardless of the mother's age.
Three years ago, a large scale study of 90 per cent of births in Sweden over 28 years found that children born to fathers over the age of 45 were at greater risk of autism, bipolar disorder, suicidal behaviour, drug abuse and ADHD.
The only surprise is why, in the face of this mounting scientific evidence – not to mention the regular imperious missives we get on the state of women’s fertility – the notion of a male biological clock remains such a taboo.
Hardly a month goes by without an expert somewhere in the world issuing a well-intentioned warning to women that their fertility is a "ticking timebomb". Earlier this year, Dr Simon Fishel of the Beacon Care IVF Fertility Clinic in Dublin – who was part of the team that pioneered the first IVF baby in 1978 – warned that women in their mid-30s often experience more complications and a greater risk of chromosomal disorders.
“One thing we can’t handle or change is our biological clock,” he said. “Once you get beyond 35, every few months is important.”
By contrast, going on the media coverage of all things fertility-related, you could be forgiven for thinking that the worst older fathers have to worry about is the risk of having a son who's more successful than they are. A study in the Journal of Translational Psychiatry published in June, which found that advanced paternal age was associated with "high IQ, strong focus on the subject of interest and little concern about 'fitting in'" attracted international headlines – including one in the Daily Mail proclaiming that "sons of older fathers are smarter and more ambitious."
"I think it's quite important that we can relieve the stigma for older fathers," said Magdalena Janecka, a co-author of the "geeky sons" study. By "stigma", she is presumably not talking about the photos of grinning fiftysomething dad-of-twins, George Clooney, or smug sixtysomething fathers, Rupert Murdoch or Ronnie Wood.
In fact, far from stigmatising them, society seems to view older fathers as a phenomenon to be celebrated – proud icons of virility. It’s difficult to imagine any woman making it through her 30s without being made acutely aware of all the things that can negatively affect her fertility: her age, weight, alcohol intake, diet, stress levels, genes, smoking habit, sleep cycle, make-up, that sexually transmitted infection she doesn’t know about, the hormonal disorder she does.
Where are the equivalent regular urgent warnings to would-be fathers that they should crack on and procreate before they hit 40? That alcohol and stress can also affect their sperm count? That they shouldn’t be standing near hot stoves, wearing tight boxer shorts, microwaving their dinner in plastic or balancing their laptop on the knees?
Even this week, in the coverage of America’s “baby crisis” – the record low fertility rate across the USA in 2016 – two words were notably absent: “men” and “fathers”.
It is true that age has a greater impact on a woman’s fertility – the impact on male fertility is “more subtle”, said Dodge. More subtle, but not insignificant. Yet it seems that, in the real world, fertility is also regarded as a predominantly female concern.
When the term “biological clock” was coined in The Washington Post in 1978, it was applied exclusively to women – not just to women, but to a particular type of woman. “The Clock Is Ticking for the Career Woman,” was the headline on the piece written by Richard Cohen.
Since then, it has been employed as a subtle pressure on women, the psychological equivalent of Aunt Lydia's cattle prod in The Handmaid's Tale, deployed at regular intervals to jolt them out of their childfree stupor.
The constant stream of reports, articles and public warnings reminding women of the risks of delaying motherhood rarely take into account all of the other things a woman – or a couple – might want to consider having in place before thinking about starting a family: an income, a suitable place to live, a stable relationship or someone to help care for the child.
They almost never take into account the fact that a significant proportion of women will choose to never have children at all. And there’s barely a mention of the part men play in either family planning, or family procrastinating.
That’s the chief problem with the notion of the female biological clock: it reduces the complexity of women’s lives to that single biological imperative.
“This is where liberation ends,” Cohen went on in that first piece. “There are some things [men] never had to worry about. Like the ticking of the biological clock.”
That may finally be about to change.
