According to a study, pregnant women who are exposed to the microscopic particles in air pollution may have metabolic disruptions and changes in important biological pathways.

According to Emory University researchers, these alterations were linked to a higher chance of several unfavorable pregnancy outcomes, including preterm birth.

While early-term deliveries (37–39 weeks gestation) are also linked to greater infant morbidity and developmental problems, preterm delivery is also linked to complications such cerebral palsy, respiratory distress syndrome, and long-term noncommunicable disease risks.

The exposure to PM2.5 is responsible for about 10% of premature births worldwide.

Lead author Donghai Liang, an associate professor of environmental health at the university’s Rollins School of Public Health, stated, “The association between air pollution and premature birth has been well established, but for the first time we were able to look at the detailed pathway and specific fine particles to identify how they are reflected in the increased risk of adverse birth outcomes.”

“This is important because if we can figure out the ‘why’ and ‘how’ then we can know better how to address it,” Liang said.

The study, which examined blood samples from 330 expectant mothers, found that two chemicals—cortisolone and lysoPE—were involved in the association between brief exposure to air pollution and an increased risk of preterm births. This suggests a possible mechanism by which air pollution causes premature labor.

In addition to providing new potential targets for preventative efforts, the study identified disturbances in protein digestion and absorption, which are critical for fetal growth and immunological function, as possible linkages between air pollution and preterm deliveries.

66 (20%) and 54 (16.4%) of the 330 women who took part in the study gave birth to preterm and early-term babies, respectively, which is much higher than the prevalence in the US population as a whole.

According to the researchers, a deeper comprehension of these pathways and pollutants’ effects on molecules is essential.

“We might be able to target some of these molecules in the future to create clinical interventions or effective strategies that could help reduce these negative health effects,” Liang said.