The association between maternal urinary Bisphenol A levels and neurodevelopment at age 2 years in Chinese boys and girls: A prospective cohort study.

The impact of maternal exposure to Bisphenol A on child cognitive development as well as its sex dimorphism remains uncertain. This study used data of 215 mothers and their children from a birth cohort in Shanghai. Urinary BPA were measured in spot urine samples of mothers at late pregnancy and children at age 2 years. Cognitive development was evaluated by Ages & Stages Questionnaires, Third Edition (ASQ-3) at age 2 years. Urinary BPA was detectable in 98.9% of mothers (geometric mean, GM: 2.6 μg/g. creatinine) and 99.8% children (GM: 3.4 μg/g. creatinine). Relative to the low and medium BPA tertiles, high tertile of maternal urinary BPA concentrations were associated with 4.8 points lower (95% CI: -8.3, -1.2) in gross motor and 3.7 points lower (95% CI: -7.4, -0.1) in problem-solving domain in girls only, with adjustment for maternal age, maternal education, pre-pregnancy BMI, passive smoking during pregnancy, parity, delivery mode, birth-weight for gestational age, child age at ASQ-3 test. This negative association remained with additional adjustment for child urinary BPA concentrations at age 2 years. No association was observed in boys. These results suggested the sex-dimorphism on the associations of maternal BPA exposure with gross motor and problem-solving domains in children at age 2 years. This study also indicated that optimal early child development should start with a healthy BPA-free "in utero" environment.