Prenatal ozone exposure is associated with children overweight and obesity: Evidence from the Shanghai Maternal-Child Pairs Cohort

Prenatal ozone (O3) exposure may disrupt normal offspring growth. However, epidemiological evidence that prenatal O3 exposure affects the physical development of offspring early in life is far from adequate. A total of 4,909 maternal–child pairs from the Shanghai Maternal–Child Pairs Cohort (Shanghai MCPC) were included. A high-resolution random forest model was utilized to evaluate prenatal exposure levels of O3 based on the home addresses of pregnant women. Group-based trajectory and mixed-effects models were used to assess associations between prenatal O3 exposure and physical parameters. Each 10 μg/m³ increase in O3 concentration was associated with 0.084, 0.048, and 0.082-unit increases in BMI for age Z score (BAZ), weight for age Z score (WAZ), and weight for length Z score (WLZ), respectively. Specifically, a 10 μg/m³ increase in O3 concentration was linked to a 1.208-fold and 1.209-fold increase in the elevated-increasing group for the BAZ and WLZ trajectories, respectively. Moreover, each 10 μg/m³ increase in prenatal O3 was associated with a 1.396-fold and 0.786-fold increase in the risk of BAZ- and length for age Z score (LAZ)-accelerated growth, respectively. Furthermore, a 10 μg/m³ increase in prenatal O3 was linked to a 1.355-fold increase in the risk of overweight and obesity (OAO). Our study revealed that prenatal O3 exposure is associated with accelerated BMI gain or decelerated body length gain in the early life of children. Prenatal O3 may also increase the risk of OAO in children for the first two years.