AS with the process itself, there's a cycle when it comes to prying into the reproductive intentions of women. Up until a certain age, you will be asked when you're planning to have children. If the questioner is of a more thoughtful bent, they might ask if you plan to have children.

Recently, I was asked the question: "Have you had your children yet?" Never has a question been so loaded.

After that certain age, people become more delicate around the topic. A bit tip-toey. It's presumed that you would love to have children but the chance is slipping away and so it's best not to pry.

Eventually, people assume it's too late anyway and they ask with gay abandon about how you've ended up as you are.

It's all pretty tedious. And more tedious still at the fact the burden is not shared. Yes, men are also asked about their procreative plans but the tone is different. The expectation of hurry and desperation is lacking from the conversation when you have it with a bloke.

Look at their role models: George Clooney (54) has just helped to produce some twins. Ronnie Wood (69) is also newly a dad of young twins. Clint Eastwood became a dad again at 67. Rod Stewart at 66. There's no rush for the boys. They're more of a catch anyway, in our gig economy, the older men with their steady incomes and property.

But wait. In 2014 Swedish research added to the growing body of evidence that dads older than 45 are more likely to have children with schizophrenia, autism and other psychiatric disorders. This hasn't seemed to make much of a dent in the narrative around women's biological clocks and men's languid attitude towards fatherhood.

Now, though, a study, led by Harvard Medical School, of almost 20,000 cycles of fertility treatment, found that sperm deteriorates. A woman with a younger partner is much more likely to have a baby.

Women aged 35 to 40 had significant benefits from having a male partner aged under 30. Women with younger lovers had success rates of 70 per cent, compared to 54 per cent when partners were in the same age bracket.

Women under 30 with male partners aged 40 to 42 were 46 per cent less likely to have a child than those with partners aged 30 to 35. Also, the risk of miscarriage is higher with an older man.

Women should find a toyboy if they wish to have a baby. Cheryl Cole (34), with her young baby daddy Liam Payne (23), is vigorously nodding.

Experts said sperm from younger men appeared to “invigorate” eggs from older women. And not just the eggs, amirite? Sorry.

It's unpleasant to sound gleeful but also, after years of the aforementioned questioning, awfully tricky to resist.

"Fertility research has focused so much on women that male factors are less well understood. The impact of age seems to focus almost exclusively on the female partner’s biological clock,” Dr Laura Dodge, from Beth Israel Deaconess Medical Centre in Boston, who was lead researcher, said.

What will the impact be of science telling men they don't have all lifetime to pass on their genes?

Nick Macklon, professor of obstetrics and gynaecology at the University of Southampton, posits: “It may help women to encourage their male partners to get a move on."

There you have it. The responsibility for having children and the desire for them falls, popular narrative and highly educated scientists would have you believe, squarely with women. As if, were it solely up to men, the human race would be extinct.

I'm not sure what the science would have us do, however. Human relationships are messy. We don't always settle down when we should, sometimes we settle when we shouldn't. Women and men are having babies later for myriad reasons. Certainly, if we all start hankering after youth then both sexes will quickly be scuppered.

But it would be nice, just so nice, if it were broadly acknowledged that when it comes to reproduction it takes two to tango.