This One Thing Affects Men’s Fertility More Than You Think

Most of their lives, women are told that, if they want to have kids, they need to think about having them sooner rather than later — especially if they want to avoid expensive fertility treatments, surrogates, or adoption. Men's fertility, women are often told, is rather fixed: If they can have children, they should be able to do so at any age. But according to one study, there's one thing that can affect men's fertility more than you'd think, and surprisingly, it's the exact same thing that affects women.

The study, carried out at the Beth Israel Deaconess Medical Center and Harvard Medical School, found that men's age can affect fertility. To conduct their study, the researchers looked at the in vitro fertilization cycles of over 7,000 couples over four years, grouping the women by their age ranges (under 30 years old, 30 to 35, 35 to 40, and 40 to 42). As scientists have already found, women's ages had a large effect on their fertility, with women under 30 seeing the highest level of success and those over 40 having more troubles with fertility.

However, within the women's age groups, another trend appeared: The older the man each woman was with, the lower her chances of success. Women under 30 who were carrying out IVF with a man between 30 and 35 years old had a 73 percent chance of having a live birth — but if their male partners were over 40, those chances dropped down to 46 percent. For women over 30, having a partner older than themselves lowered their chances of a live birth by 11 percent.

"This information provides new insights and reminds us that it takes two to tango," Nick Macklon, professor of obstetrics and gynecology at the University of Southampton, told The Telegraph this week. "It's not just down to the age of the woman."

Past research has already linked men's increasing age to a higher risk of miscarriage and fetal defects, but the new study's findings throw extra weight behind the idea that men — just like women — need to pay attention to their biological clocks. Women's age alone doesn't determine a couple's ability to procreate, and it's about time we started educating people on that.

"Infertility has for far too long been treated as an all-female issue," Geeta Nargund, the medical director at Create Fertility, wrote for The Guardian in June. "We need to break down the silence, improve education and give men the opportunity to open up and discuss a topic that can be as painful for them as it is for their female partners."

If couples don't want to receive unhappy news when they do decide to have children, experts say, society needs to start changing the conversation around fertility — and that's a conversation best had sooner, rather than later.