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 4909 maternal-child pairs from the Shanghai Maternal-Child Pairs Cohort 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 body mass index (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 increases 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.