Adverse Pregnancy Outcomes Linked to Climate Change

FOR IMMEDIATE RELEASE:
SAM DELSON
(916) 764-0955 (C)
Sam.Delson@oehha.ca.gov

SACRAMENTO – Higher rates of preterm birth, low birth weight and stillbirth are linked to increased heat, ozone and fine particulate matter, according to a meta-analysis released today and co-authored by scientists at the California Office of Environmental Health Hazard Assessment (OEHHA). The analysis summarizes the evidence from 68 studies and includes 32.8 million U.S. births.

The research – published in the Journal of the American Medical Association by scientists from OEHHA, the Permanente Medical Group and other institutions – concluded that “increasingly common environmental exposures exacerbated by climate change are significantly associated with serious adverse pregnancy outcomes across the U.S.”

“This groundbreaking research provides an important contribution to quantifying the relationship between heat and air pollution and adverse pregnancy outcomes,” said OEHHA Director Dr. Lauren Zeise. “Research in this area is critical to furthering our understanding and ultimately addressing these very real consequences of climate change.”

OEHHA’s Dr. Rupa Basu said the research “suggests that younger mothers and racial/ethnic minority mothers were at greatest risk from pregnancy outcomes such as preterm delivery.” Dr. Basu co-authored the new analysis and was the principal author of several of the studies that were reviewed. She added, “By identifying pregnant women as vulnerable to heat and air pollution exposures, these findings can help guide future preventive efforts for obstetricians and for women and families across the country.”

The causes of preterm birth, low birthweight and stillbirth are complex, the researchers noted, and several ways that heat and air pollutants can cause these effects have been suggested. Toxic fine particulate air pollution can trigger inflammation of the lungs and other organs throughout the body, and interfere with the proper functioning of the nervous system. Heat can contribute to premature birth through dehydration, which can initiate labor and also impair the growth of the fetus.

The study is titled "Association of Air Pollution and Heat With Preterm Birth, Low Birth Weight, and Stillbirth in the US."

OEHHA’s mission is to protect and enhance the health of Californians and our state’s environment through scientific evaluations that inform, support, and guide regulatory and other actions.

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