Exposure to PM2.5 May Be Associated with Adverse Birth Outcomes: Study Finds - Video

For pregnant women, exposure to fine particulate air pollution (PM2.5) was associated with altered immune responses that can lead to adverse birth outcomes, according to a new study led by Harvard T.H. Chan School of Public Health. The study was published in Science Advances.

Key points from the study are:

Exposure to PM2.5 was associated with higher levels of inflammation among pregnant women, potentially leading to adverse birth outcomes.

Study examined PM2.5 and maternal and fetal health on a single-cell level, using an innovative technology to detect how pollution modified the DNA within individual cells.

Findings provide new understanding of the biological pathways through which air pollution affects pregnancy and birth outcomes, and further highlight the importance of policy and clinical interventions to limit air pollution exposure for pregnant women.

“This study represents a substantial step forward in understanding the biological pathways through which PM2.5 exposure affects pregnancy, maternal health, and fetal development. Its advanced methodology represents a significant innovation for how we study immune responses to environmental exposures,” said corresponding author Kari Nadeau, John Rock Professor of Climate and Population Studies and chair of the Department of Environmental Health.

To understand the associations on a cellular level, the researchers used air quality data collected by the Environmental Protection Agency to calculate study participants’ average PM2.5 exposure. Participants were both non-pregnant women and 20-week pregnant women. The researchers then used an innovative technology to understand how pollution modified the DNA of participants’ individual cells. Within each cell they were able to map changes to histones, the proteins that help control the release of cytokines—proteins that help control inflammation in the body and that can affect pregnancy.

The study found that PM2.5 exposure can influence the histone profiles of pregnant women, disrupting the normal balance of cytokine genes and leading to increased inflammation in both women and fetuses. In pregnant women, this increase in inflammation can correspond with adverse pregnancy outcomes.

Reference: Youn Soo Jung et al., Impact of air pollution exposure on cytokines and histone modification profiles at single-cell levels during pregnancy.Sci. Adv.10,eadp5227(2024).DOI:10.1126/sciadv.adp5227