US Heat Waves Linked With Small Rise in Preterm Births

Multiple days of high temperatures were associated with a slight uptick of preterm and early-term births—those that occur between 28 and 37 weeks’ gestation and between 37 and 39 weeks’ gestation, respectively—a recent study in JAMA Network Open found. The findings were based on data from more than 53 million births in the 50 most populated US cities between 1993 and 2017.