Post by Harvard Medical School

Mounting evidence links extreme heat to preterm birth, low birth weight, and stillbirth, indicating that rising temperatures are contributing to worse health outcomes for pregnant people and newborns. A study led by led by Harvard Medical School researchers at Beth Israel Deaconess Medical Center suggests that low-dose aspirin — which is routinely used in some pregnancies to reduce the risk of conditions such as preeclampsia — could be valuable for reducing heat-related preterm births. The analysis drew on data from a large, NIH-funded randomized clinical trial known as the Global Network for Women’s and Children’s Health Research ASPIRIN trial. It found that exposure to humid heat during pregnancy was associated with higher odds of preterm birth — but not among those who took low-dose aspirin starting early in pregnancy. “The increasing global prevalence of heat stress warrants testing the effects of aspirin more broadly among pregnant people, as well as its safety with respect to perinatal mortality,” said senior author Blair Wylie, HMS professor of obstetrics, gynecology, and reproductive biology at Beth Israel Deaconess. The work underscores how rising temperatures are reshaping risks for pregnant people and their babies and suggests that low-dose aspirin could offer a practical, low-cost way to reduce heat-related risk.