Later childbirth might mean a longer life

Attention, 30-something single ladies: If you’re tired of people dropping not-so-subtle hints about having kids while you still have the eggs and energy, you can (probably, politely) tell them to back off.

A Boston University School of Medicine study found that women who can still give birth naturally after age 33 have a higher chance of living to extreme old age than those who had their last child before age 30.

But the report, published in the online version of the journal Menopause in April, “does not mean women should wait to have children at older ages in order to improve their own chances of living longer,” said Boston University professor of medicine and study co-author, Thomas Perls.

“The natural ability to have a child at an older age likely indicates that a woman’s reproductive system is aging slowly, and therefore so is the rest of her body.” Some women’s biological clocks simply run slower than most.

Perls and his colleagues analyzed data from the Long Life Family Study, a survey of 551 families, many of whose members lived to a ripe old age. They determined the ages at which 462 women had their last child and how long they ended up living. Turns out women who gave birth to their last child after 33 were twice as likely to live to 95 years or older, compared with those who had their last child by age 29.

The researchers suspect that the former group’s DNA might harbor genetic variants that slow aging and lower the risk for age-related diseases that can hamper fertility (like ovarian cancer or diabetes).

Women with such variants could presumably bear children for a longer period of time, boosting their chances of passing these genes down to future generations — meaning we may have women to thank for the evolution of longevity genes. It could also explain why of the people who live to be 100 or older, 85% are women, compared to only 15% of men.

Earlier studies have unearthed similar insights. Take the ongoing New England Centenarian Study, which found that women who had children after 40 were a whopping four times more likely to live to 100 than women who had their last child at a younger age.

Given the possible link between longevity and a longer fertility window, Perls’ findings also suggest that researchers should further investigate the genetic influences of reproductive fitness, since they might also affect aging rates and vulnerability to age-related diseases.

Eventually, Perls hopes to identify the genetic variants that make some women age slower. Understanding the pathways they govern could help scientists develop drugs that produce the same effect.

So even if your biological clock is ticking, it might still be a while before its alarm goes off — depending on your genes.