By Stacia Pelletier | June 18, 2025
A new USC-led study published in Environmental Science & Technology reveals that exposure to wildfire smoke and heat stress—particularly in the month before conception and during early pregnancy—can increase the risk of adverse birth outcomes, such as small-for-gestational-age and low-birth-weight infants. Led by Dr. Roxana Khalili and conducted through the MADRES cohort, the study highlights how women living in climate-vulnerable neighborhoods face even greater risks, with heat stress effects on birth outcomes nearly doubling in these areas. The findings underscore the urgent need for community-level interventions that address the cumulative impacts of environmental and socioeconomic stressors, especially as wildfire seasons grow longer and more intense.
This study was supported by the National Institute of Environmental Health Sciences, National Institutes of Health (NIH) [P50MD015705, P50ES026086, R01ES027409, P30ES007048], the Environmental Protection Agency [83615801], the National Heart Lung and Blood Institute (NIH) [P20HL176204] and the USC Provost Fund.