Prenatal exposure to persistent organic pollutants and body mass index trajectories from birth to age 13.

Prenatal exposure to persistent organic pollutants (POPs) has been linked to growth and adiposity development in children. However, only few studies considered the growth dynamic and none have tracked children into adolescence. This study included 450 mother-child pairs from the PELAGIE cohort (France). Polychlorinated biphenyls (PCBs), Organochlorine pesticides (OCs), Polybrominated diphenyl ethers (PBDEs), and Perfluoroalkyl substances (PFAS) were measured in cord blood. A latent class growth model identified four types of BMI z-score (zBMI) trajectories from birth to 13 years. Associations between each POP and zBMI trajectories were assessed using multinomial regressions. POP mixture effects were explored using Quantile G-computation and grouped Weighted Quantile Sum regressions. All analyses were stratified by sex and adjusted for confounders. In girls, all PCBs were associated with higher odds of the "Low-High" trajectory (e.g., OR (95%CI) = 3.78 (1.58; 9.05) per doubling of PCB 153). The PCB mixture, HCB and β-HCH also tended to favor this trajectory, whereas dieldrin was associated with a lower odds. In boys, the "High-High" and "Low-High" trajectories were significantly associated with the POP and PFAS mixtures (with PFuDA, PFDA and PFOA as main contributors). Our study suggests sex-specific associations of prenatal exposure to POPs mixtures with growth dynamics until adolescence known as risk factors for adult cardiovascular diseases. Although these results need to be confirmed in larger studies, girls seem more vulnerable to prenatal exposure to PCBs while boys seem more vulnerable to prenatal exposure to PFAS.