The percentage of preterm births in the United States has been on the rise for decades, and today around 1 in 10 infants who are delivered in the U.S. have gestation times of 37 weeks or fewer. These preterm infants have significantly higher mortality rates than infants who have 37 to 41 weeks of gestation. And this pregnancy-related issue disproportionately affects people of color who may lack access to the quality healthcare that’s often needed — including ultrasounds and fetal fibronectin tests — to diagnose preterm labor. But what if there was a simple, cost-effective way to screen for premature births that one could do on their own? The technology company WHOOP says they’ve uncovered one.
While WHOOP wearables are primarily fitness-focused, they’ve moved into the pregnancy coaching space with features that include menstrual cycle tracking based on heart rate variability (HRV). And a new reproductive health study conducted by the Boston-based company has revealed some potentially groundbreaking information about the HRV of people who are pregnant; HRV can serve as an indicator of preterm birth risk. WHOOP data shows that HRV trends can be used to determine if labors will be pre- or full-terms about 7 weeks before they happen. Over the course of a pregnancy, HRV steadily declines, but hits an inflection point and begins to rise around 7 weeks before birth. WHOOP says this biomarker accurately predicts the likely delivery dates for both premature and full-term pregnancies.
While there may be some implicit bias in a company-conducted study that’s yet to get peer reviewed, it is the largest study of its kind, analyzing the remotely-collected physiological data of 241 pregnancies in 42 U.S. states and 16 countries. Dr. Elizabeth Cherot, Chief Medical Officer of the medical group Axia Women’s Health, says, “WHOOP has identified a new biomarker that merits additional clinical research alongside the implementation of its wearable technology. Accessible, noninvasive screening options for premature birth can serve as early warning signs for pregnant people, giving them more time to find and administer interventions to improve health outcomes.”
WHOOP CEO Will Ahmed says, “We’ve worked vigorously to incorporate this research into the WHOOP app. We will continue to update the feature on a weekly basis for our members.” These features include a Weekly Performance Assessment in which the HRV data that’s collected by the WHOOP band is tracked for week-over-week changes in HRV. But these novel findings are in no way limited to one brand of wearables: the Oura Ring, Apple Watch, Samsung Galaxy Watch, Fitbits, Garmin wearables, and more all track HRV. So the key to predicting — and thus mitigating the dangers of — premature birth may already be in the hands of millions of women.