For centuries women have been burdened with the responsibility of the ticking fertility timebomb, having to procreate as early as possible while Mick Jagger welcomes his eighth child at 73-years-old.
But a new study has revealed that females aren’t alone in carrying the reproductive responsibility. It appears as though male fertility doesn’t last forever either, and their age does have an impact on baby-making chances.
In fact, the researchers say it can have a “substantial impact” on the ability to start a family if left too late.
It has long been presumed that fatherhood has far fewer time constraints than their partner, whose fertility will drop sharply in her mid-thirties, but Laura Dodge, from Harvard University, says: “When making this decision, they should also be considering the man’s age.”
The findings are the result of a study into IVF cases, which showed that delivery rates are affected by the age of the male partner, as well as the mother, and become less successful as they get older.
Looking at 15-years-worth of IVF data, for 19,000 IVF cycles given to almost 8,000 couples, they broke down the information into four categories: under 30, 30–35 years old, 35–40, and 40–42.
The cumulative live birth rate was lowest in couples where the female partner was aged 40-42, which was unsurprising to the team, but in younger bands of women the age of their male counterpart did directly influence probability of conceiving.
Cumulative live birth rates followed a trend of declining as the male partner grew older, irrespective of the woman’s age under 40.
“Women aged 35–40 did significantly benefit from having a male partner who is under age 30, in that they see a nearly 30% relative improvement in cumulative incidence of live birth when compared to women whose partner is 30–35 – from 54% to 70%,” said Dodge.
Although they have drawn parallels between older men and declining fertility for both parties, the researchers haven’t reached a full conclusion about why this is the case.
They speculate that it could be related to sperm damage as men get older. Even though men produce fresh sperm every day, the cells the sperm are made from gather their own mutations, and older sperm carries more DNA damage.
Nick Macklon, Professor of Obstetrics and Gynaecology, told The Guardian: ““It may help women to encourage their male partners to get a move on. We know from a number of studies that one of the reasons why women are having babies later is because men are sometimes slow to support the idea.”
“This reminds us that it takes two to tango and it’s not just down to the age of the woman.”
In the UK, IVF guidelines, as laid out by the The National Institute for Health and Care Excellence (NICE) recommended that IVF should be offered to women under 43 years of age who have been trying to get pregnant through regular unprotected sex for two years.