Neuromotor effects of early-life exposure to a mixture of endocrine disruptors in Belgian preschool children.

Objective: Children gradually develop motor skills that enable them to move efficiently in various daily activities such as self-care, academics and sports. The impact of prenatal exposure to endocrine disruptors (EDCs) on these performances remains understudied and current results are inconsistent. This study aims at examining the neuromotor function of Belgian preschoolers exposed in utero to a mixture of some of these chemicals.

Methods: From 2014 to 2016, 66 children (35 boys and 31 girls) were recruited for a longitudinal cohort study. Two polychlorinated biphenyls (PCBs) and four perfluoroalkyl substances (PFASs) were measured in cord serum. A standardized motor evaluation, the Movement Assessment Battery for Children II (MABC-II), and a clinical sensori-motor assessment examining minor neurological dysfunction were administered at 6 years of age. The impact of the mixture of EDCs on neuromotor outcome measures was evaluated using two validated statistical models. Sex-specific analyses were also conducted.

Results: Using a principal component analysis, a negative association was identified between a mixture of PCB-153 and - 180 and the Total Clinical examination score in the whole population (β (95% CI) = -15.8 (-26.51; -5.09), p = 0.005). After stratification by sex, negative associations were observed between the Gross Motor score of the MABC-II test and prenatal exposure to a mixture of PFASs and PCB-180, specifically in boys. This association was consistent across both the weighted quantile sum regression model (β (95% CI) = -2.36 (-3.42; -0.62), p = 0.023) and the principal component approach (β (95% CI) = -1.09 (-2.15; -0.13), p = 0.044).

Conclusion: Our findings suggest that the neuromotor function of young children is adversely influenced by prenatal exposure to toxicants in a sex-specific manner.