Maternal exposure to air pollution — specifically particulate matter (PM2.5, PM10) and nitrogen dioxide (NO2) — during the three months prior to conception may increase the risk of childhood obesity up to two years after birth, according to a study published on Thursday.
Previous research has connected air pollution exposure during pregnancy to a range of health issues in children, such as respiratory problems and an elevated risk of chronic diseases like obesity and heart conditions. However, the new study, conducted by an international team of researchers from the US and China, focuses on the preconception period — defined as the three months before pregnancy begins.
The researchers emphasized that environmental exposures during this critical timeframe could impact the health of sperm and eggs, which are in their final stages of development. The findings were detailed in a paper published in the journal Environmental Research.
The study analyzed data from 5,834 mother-child pairs recruited from maternity clinics in Shanghai.
The results revealed that increased exposure to PM2.5, PM10, and NO2 during the preconception period was associated with higher BMI or BMIZ — a standardized score comparing a child’s BMI with peers of the same age and sex.
“These findings imply that the three months before conception are crucial, and individuals planning to have children should consider measures to reduce air pollution exposure to lower their children’s risk of obesity,” said Jiawen Liao, postdoctoral research associate at the Keck School of Medicine, University of Southern California (USC).
The study found that higher exposure to PM2.5 during the preconception period was linked to a 0.078 increase in child BMIZ at age two, while greater exposure to PM10 was associated with a 0.093 kg/m² increase in BMI at the same age.
From six months onward, children exposed to higher levels of all three pollutants before conception exhibited higher weight, BMI, and BMIZ growth rates.
“Although the effect size is small, the widespread nature of air pollution means that its impact on childhood obesity risk could be substantial and may begin even before pregnancy,” said Zhanghua Chen, assistant professor at the Keck School.
While the study is observational and further research is necessary to establish causation, the findings highlight the importance of minimizing air pollution exposure during the preconception period. The researchers urged individuals to take proactive steps to reduce potential risks to themselves and their children.
(Inputs from IANS)
