It is often women who receive the comment “your biological clock is ticking”, but the same can also be said for the man.
For years women have accepted that they have a biological clock which starts to tick as they get into their thirties, which they can either act on or ignore.
But men have happily reassured themselves that if Charlie Chaplin and more recently Mick Jagger can become a dad in their seventies – they have nothing to worry about for decades.
But scientists have now found that for every year the man is aged over 24 years, the chances of conceiving within six months fall by 2% a year and within 12 months by 3% a year.
Just to pile the pressure on the men, women whose partners are five years or more older than them have less chance of conceiving within 12 months than those with partners of the same age or younger.
The research was carried out by scientists from Bristol and Brunel Universities and was published in the Journal of Human Reproduction*.
It was found that, in couples who ultimately did prove to be fertile, the chance it will take more than 12 months to conceive doubles from around 8% if the man is under 25 years to about 15% if he’s over 35.
Couples taking part in the survey were 18 weeks pregnant when they completed a survey about how long it had taken to conceive. Of the 8,515 planned pregnancies, 74% took under six months, 14% 6 to 12 months and 12% more than a year.
*W.C.L Ford et al. Increasing paternal age is associated with delayed conception in a large population of fertile couples: evidence for declining fecundity in older men. Human Reproduction. Vol. 15. No. 8. pp1703-1708