This Health Tracker May Be Able To Tell When You’ll Give Birth Based On Your Heart Rate

Due dates are notoriously tricky — you look forward to them as the day you might potentially meet your baby (and be free of your pesky pregnancy side effects). But research shows that only around 5% of people give birth on their actual due date. So, when you’re trying to prepare for this momentous occasion, having a firmer idea of when your birth might actually occur is, you know, pretty helpful. One fitness tracker brand, WHOOP, says they may have found a key data point that signals when your labor may actually begin.

Like you’d expect from a health tracker, WHOOP assesses your quality of sleep, physical exertion, and recovery. In an interview with the Working Hard, Hardly Working podcast, WHOOP founder Will Ahmed spoke about the company’s latest discovery, which may be of particular interest to pregnant people. Ahmed explains that, in a small study, his company observed that pregnant women’s heart rate variability (HRV) steadily declines throughout their pregnancy. Then, at some point (usually around the 33rd week of gestation), they would have “a sharp inflection” where their HRV would rise again.

So, researchers at WHOOP gathered 1,200 pregnant customers for a larger study, according to a news release on their website. The goal: to determine whether this sudden uptick in HRV was specific to the 33rd week of pregnancy, or a predictor that happened seven weeks prior to delivery. Roughly 10% of participants had pre-term births, Ahmed says, and it became clear that this shift in HRV happened seven weeks before the women delivered. In short, it could help predict when your baby may actually arrive.

Comments on the clip of Ahmed’s interview are varied, from women wishing they’d had this data point to dreading the idea of knowing precisely when they’d go into labor. “As someone that had one at 40+1 and another at 34+3, I would’ve LOVED to had a heads up!!” says one commenter. “Could you imagine suddenly having a 7 week birth countdown pop up on your health app? my heart rate would definitely become more varied,” says another. Most of the discussion is positive though, with women acknowledging the potential this information has to impact the outcomes of preterm babies.

WHOOP’s discovery is part of a major moment in health tracker technology, in which brands are investing in features specific to women’s health. Oura recently announced a partnership with Clue, the period and pregnancy tracking app, and UC Berkeley to conduct research on how perimenopause affects women’s health, and has some of the more detailed menstrual cycle insights of health trackers on the market today. Apple Watches are capable of tracking cycles and ovulation as well.

Of course, always talk to your doctor about any concerning info you see on your health tracker’s insights. Whatever device you have, it’s nice to know there may be a little hint, hiding among all that other biometric data, of when your baby will actually be born.