NEW DELHI: Exposure to the tiny particles in air pollution during pregnancy can disrupt maternal metabolisms, altering key biological pathways, according to a study.
These changes were associated with an increased risk of various negative birth outcomes, including premature birth, said researchers from Emory University.
Preterm birth is also linked to complications such as cerebral palsy, respiratory distress syndrome, and long-term noncommunicable disease risks, while early-term births (37-39 weeks of gestation) are also associated with increased neonatal morbidity and developmental challenges.
Approximately 10 per cent of the preterm births in the world are attributable to PM2.5 exposure.
"The link 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," said lead author Donghai Liang, and associate professor of environmental health at the varsity’s Rollins School of Public Health.
"This is important because if we can figure out the 'why' and 'how' then we can know better how to address it," Liang added.
The study, which analysed blood samples provided by 330 pregnant women, identified two substances -- cortexolone and lysoPE -- as factors in the relationship between short-term air pollution exposure and elevated risk of early births, offering a potential mechanism through which air pollution triggers premature labour.
The study highlighted disruptions in protein digestion and absorption -- which are vital to foetal development and immune function -- as potential links between air pollution and early births, also offering new potential targets for prevention efforts.
Of the 330 women who participated in the study, 66 (20 per cent) delivered preterm babies and 54 (16.4 per cent) delivered early-term babies, both of which are significantly higher than the prevalence in the general US population.
The researchers said it is critical to gain a better understanding of these pathways and molecules affected by pollution.
“In the future, we may be able to target some of these molecules to develop effective strategies or clinical interventions that could help reduce these adverse health effects," Liang noted.