Unless you have spent the last 24 hours under a rock with no WiFi, you’ve definitely heard the good news that Beyoncé finally had her twins. Earlier in June, Amal and George Clooney also welcomed twins into the world, adding to the growing list of celebs with twins in their broods. Coincidence? Maybe. But it could also be a trend related to maternal age — and science.
Besides having new twins (and super successful careers), Clooney and Beyoncé have an age range in common: Bey is 35, and Amal is 39.
Recent studies have shown that once a woman passes age 35, her chances of having twins goes way up. According to Scientific American, a woman is four times more likely to give birth to fraternal (AKA non-identical) twins at age 37 compared to age 18. And since more women than ever are now having their first babies in their thirties — a cohort that includes a whole lot of millennial women — Hollywood’s twin baby boom helps shed light on a fertility trend that’s hitting millennial women especially close to home.
More twins are being born in the US than ever before, thanks to the convergence of age-related hormonal shifts and evolving fertility science. According to a 2014 report from the Centers for Disease Control and Prevention, the number of twins born in the US reached an all-time high in 2014, with 23.9 twins for every 1,000 births in 2014.
Seeing a woman in her mid-to-late thirties (or beyond) who is pregnant with twins may lead people to assume that the woman has undergone some sort of fertility treatment. It’s true that advances in fertility treatments and alternative methods of conception such as in vitro fertilization (IVF) do have something to do with the overall twin boom.
Twins or other multiples can be more common among IVF patients, many of whom opt to have more than one embryo implanted at a time, which ends up boosting the odds of multiple births. But other research shows that it’s not just fertility medicine that contributes to higher twin births among moms who are in their thirties or later.
As modern medicine continues to develop and refine ways to conceive when it becomes more of a struggle (which it can be for women in their mid-thirties and beyond), more women are able to have babies than in previous decades when IVF and other treatments didn’t exist or were still very new.
But the other big factor at play is totally biological: hormones. According to a 2006 study that collected data from the reproductive cycles of 507 women ages 24 through 41 for 959 menstrual cycles, women who age 35 through 41 have a pronounced shift in hormones that makes them more likely to have twins.
Compared to women in their twenties, women in their thirties had higher levels of a pregnancy-related hormone called follicle-stimulating hormone (FSH). As a result, women in their thirties were likelier to prepare more than one egg during their menstrual cycle.
None of us earthly beings know if Beyoncé or Amal used any kind of fertility treatment to have their twins and, of course, it’s nobody’s business if they did. But even if they didn’t, the combination of their ages and the right timing could have led to having multiples. However they conceived their babies, it’s exciting to live in a time when so many twins are being born. It’s also great to know that moms well into their thirties and beyond have choices when they want to have kids.
What do you think of all these celeb twin births? Tell us on Twitter @BritandCo.
(Photos via Getty)