COLUMBUS, Ohio-Research published in JAMA Network Open reveals that prolonged periods of extreme heat, characteristic of heat waves, are linked to increased rates of preterm and early-term births across the United States. Analyzing data from 53 million births in major metropolitan areas over 25 years, the study found a 2% rise in preterm births and a 1% increase in early-term births during heat waves between May and September.
Particularly alarming is the higher incidence of preterm births among older mothers after heat waves. Vulnerable groups, such as younger mothers from minority racial backgrounds with lower education levels, are disproportionately affected, likely due to disparities in access to air conditioning and higher exposure to outdoor heat. Biological mechanisms, including reduced blood flow and increased oxidative stress, may contribute to premature labor during heat exposure. Given the increasing frequency and severity of heat waves globally, understanding their health impacts, especially on vulnerable populations, is critical. This research coincides with the onset of a heat wave in the U.S. Southwest, underscoring the urgent need to address the health risks posed by rising temperatures.
