Does the ‘fertility cliff’ really hit at 35?

One number is inescapable for women who want children: 35.

- Dani Blum

Give birth at that age or past it, and doctors will say you are at “advanced maternal age”. That term is the newer, softer version of an older designation: a “geriatric pregnancy”.

Fertility doctors and researchers say that many women see 35 as a tipping point. After that, the theory goes, getting pregnant and carrying to term becomes really, really hard.

That line of thinking is pervasive. It is also not totally true.

The concept of a “fertility cliff” “has really taken hold, and especially in the American imagination, since the 1970s”, said Dr Emily Mann, a sociologist at the University of South Carolina.

“It’s like a buzzword,” she added.

And yet more and more women who are 35 and older are getting pregnant.

Data from the Centers for Disease Control and Prevention released in July showed that while the general US fertility rate dropped in 2024 - with 53.8 births per 1,000 women of reproductive age — the rates of women who gave birth at age 35 to 39 remained steady. And the rates of women older than 40 who gave birth rose by 2 per cent, according to the data.

That may, at least partly, be the result of shifting economic and social trends. More women say they are waiting to get pregnant because they cannot yet afford to raise children, because they want to complete their education and pay off the costs of a degree, or because they want to find the right partner.

And as assisted reproductive technologies have improved, more women have sought out procedures like in-vitro fertilisation, which can help people become pregnant at a later age.

“We know that it’s typically really easy for a younger woman to get pregnant compared with an older woman,” Dr Mann said. “But that’s population-level data. That doesn’t necessarily tell you, as an individual, how hard or easy it might be.”