Study Reveals Maternal PM2.5 Exposure Disrupts Immune Health in Pregnancy

New Delhi: Exposure to fine particulate matter (PM2.5) in air pollution disrupts immune responses and alters gene regulation in pregnant women and their newborns, a study has found. Published in Science Advances, the research, led by Youn Soo Jung from Harvard T.H. Chan School of Public Health and collaborators, highlights the health impacts of PM2.5 during pregnancy.

The study analysed blood samples from 168 pregnant women and 151 non-pregnant women in California, along with cord blood samples from 33 newborns. It found that PM2.5 exposure during the second trimester reduced levels of key immune molecules, such as IL-1RA, IL-8, IL-18, and IL-27, in pregnant women.

These molecules are essential for regulating inflammation and immune responses. Newborns of mothers exposed to high PM2.5 levels had lower levels of IL-27 in their cord blood, indicating potential effects on their developing immune systems.

The research also revealed that PM2.5 altered epigenetic markers, such as histones H3K9ac and H3K27ac, which play crucial roles in gene regulation within immune cells.

Dr Kari C Nadeau, a professor at Harvard University and one of the lead researchers, said, "Our findings reveal how air pollution interferes with maternal and fetal immune health through mechanisms that involve both immune dysregulation and epigenetic modifications. These insights could guide preventive strategies and policies to safeguard public health."

The study also showed a correlation between maternal and neonatal immune responses, which were disrupted under high PM2.5 exposure. Co-author Dr Nima Aghaeepour from Stanford University explained, "High exposure to fine particulate matter not only affects maternal health but also has measurable impacts on the immune environment of the newborn, which may have lifelong consequences."

Researchers identified the three months before blood or cord blood collection as the most critical period for PM2.5 exposure effects. Dr Purvesh Khatri, another lead researcher, emphasized, "Timing is everything. Understanding these sensitive windows of exposure allows us to better protect pregnant women and their children."

The study calls for stricter air quality regulations to protect pregnant women and developing fetuses. Dr Anne R Waldrop of Stanford University remarked, "Reducing air pollution isn't just about the environment; it's a public health priority. Pregnant women should be shielded from these harmful exposures."

Participants were recruited from Fresno and the Bay Area in California, regions with varying air quality. Advanced techniques, such as a customized Luminex assay for cytokine profiling and EpiTOF for analyzing histone modifications, were used.

Future research will explore long-term health outcomes for children affected by maternal PM2.5 exposure. Dr Nadeau concluded, "This is just the beginning of understanding how the environment shapes health across generations."