New Delhi, Nov 30 : Pregnant women's exposure to fine particulate air pollution (PM2.5) may alter immune responses, leading to adverse birth outcomes, according to a new study.

While previous research linked PM2.5 exposure to maternal and child health complications including preeclampsia, low birth weight, and developmental delays in early childhood, the new study, published in Science Advances, is the first to examine the relationship between PM2.5 and maternal and foetal health.

Researchers at the Harvard T.H. Chan School of Public Health focussed on understanding air pollutants' impact on a single-cell level.

Kari Nadeau, Professor of Climate and Population Studies at the varsity said that the findings showcase 'a substantial step forward in understanding the biological pathways by which PM2.5 exposure affects pregnancy, maternal health, and foetal development'.

The use of advanced methodology also can change the way 'how we study immune responses to environmental exposures,' Nadeau said.

The study included participants both non-pregnant women and 20-week pregnant women. Using an innovative technology, the team examined 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 foetuses. In pregnant women, this increase in inflammation can correspond with adverse pregnancy outcomes.

The study highlights the importance of minimising air pollution exposure in pregnant women to protect maternal and foetal health.

The researchers also urged for policy interventions to improve air quality, and to provide clinical guidelines to help pregnant women reduce their exposure to pollution.

/IANS