Prenatal Bisphenol A Exposure and Sex-Differentiated Childhood BMI Over Time: A Longitudinal Korean Cohort Study.

BACKGROUND

Prenatal exposure to bisphenol A (BPA), an endocrine-disrupting chemical, may influence childhood obesity. Evidence on sex-specific effects remains inconsistent.

METHODS

We analysed 528 mother-child pairs from a Korean birth cohort. Maternal urinary BPA concentrations were measured during mid-pregnancy. Children's BMI and BMI Z-score were assessed at ages 2, 4, 6, 8, and 10 years. Associations were estimated using linear and mixed-effects models, stratified by sex and adjusted for maternal and child covariates.

RESULTS

The mean maternal BPA concentration was 2.3 μg/g creatinine. BPA exposure was positively associated with BMI and BMI Z-score in boys but negatively associated in girls. At age 10, this divergence was most apparent. Mixed-effects models showed a 0.13 kg/m2 (95% CI: 0.01, 0.25) increase in BMI among boys and a 0.20 kg/m2 (95% CI: -0.32, -0.08) decrease among girls per 1-unit increase in log-transformed BPA. Similar patterns were observed for BMI Z-score.

CONCLUSIONS

Prenatal BPA exposure exhibited sexually dimorphic associations with BMI from early childhood to age 10. These findings underscore the importance of considering sex-specific effects in environmental health research and support policies to reduce BPA exposure during pregnancy.