CHHS News

Air Pollution May be Responsible for One-Third of All U.S. Stillbirths

Dr. Anna Pollack from CHHS’s Department of Global and Community Health and her colleagues published one of the largest studies on labor and delivery in the U.S. in the International Journal of Environmental Research and Public Health. The study—led by Dr. Pauline Mendola of the Eunice Kennedy Shriver National Institute of Child Health and Human Development—examined the link between stillbirths and air pollution. Specifically, it looked at chronic and acute exposure to air pollution for 228,438 deliveries in twelve clinical locations over the span of six years.

The research team found that the risk for stillbirth—loss of pregnancy after twenty weeks gestation—was increased after both acute and chronic exposure, although it was more prevalent in the latter. One air pollutant, Ozone (O3), was associated with a 13-22% increased risk of stillbirth. These findings suggest that exposure to this pollutant may be responsible for 8,000 stillbirths in the U.S. per year – that’s approximately one-third of all U.S. stillbirths.

Pollack explains, “Stillbirths are a significant public health problem. Unfortunately, we can’t really change many factors related to stillbirths (e.g., genetics, pregnancy and birth complications). That’s why we wanted to determine if there was a link between stillbirths and exposure to common air pollutants. Finding this link and knowing how many stillbirths might be able to be avoided can provide an opportunity for intervention on a large scale.”

The research team suspects the true association might be even stronger than they observed due to the large size of the study. As next steps, they recommend additional studies—perhaps with more nuanced measurements of exposure—to see if their findings are confirmed.