Study Reveals Exposure to Air Pollution Before Conception Increases Child's Risk of Higher BMI - Video

In a study of more than 5,000 mothers and their children, exposure to air pollution during the three months before pregnancy predicted higher child body mass index (BMI) and related obesity risk factors up to two years of age. Findings from the study were published in the journal Environmental Research.

Researchers studied 5,834 mother-child pairs recruited from maternity clinics in Shanghai. They found that greater exposure to PM2.5, PM10 and NO2 before pregnancy was linked to increases in BMI or BMIZ, a standardized score that shows how a child’s

BMI compares to others of the same age and sex.

To calculate air pollution exposure during the preconception period, the researchers developed state-of-the-art machine learning models. Researchers used a combination of satellite data, pollutant simulations and meteorological factors to estimate daily pollution exposure at each participant’s home address.

After birth, researchers also collected electronic medical records data of children’s weight and height at three-month intervals until age two. They used this data to calculate growth rate of weight, BMI, and BMIZ. They then compared participants with a relatively low exposure level to those with a relatively high exposure level to quantify how air pollution exposure was linked to different child outcomes.

A higher level of exposure to PM2.5 during the preconception period was associated with a 0.078 increase in child BMIZ at age two. A higher level of exposure to PM10 was associated with a 0.093 kg/m2 increase in BMI at age two. From six months onward, children with higher preconception exposure to all three pollutants had higher weight, BMI and BMIZ growth rates.

“The magnitude is small, but because air pollution is widespread and everybody is exposed, the risk of air pollution exposure on children’s obesity risk may be substantial and may start before their mothers’ pregnancy,” said Zhanghua Chen, PhD, an assistant professor of population and public health sciences at the Keck School of Medicine and the study’s senior author.

Reference: Liao, J., Yan, W., Zhang, Y., Berhane, K., Chen, W., Yang, Zair pollution,bmi,environmental research,PM, ... & Chen, Z. (2024). Associations of Preconception Air Pollution Exposure with Growth Trajectory in Young Children: A Prospective Cohort Study. Environmental Research, 120665.