Early life bisphenol A exposure and neurobehavior at 8years of age: Identifying windows of heightened vulnerability.

The authors explored windows of vulnerability to BPA exposure in a multiethnic cohort of 228 mothers and their children from Cincinnati, Ohio. They measured urinary BPA concentrations at up to two prenatal and six postnatal time points from the 2nd trimester of pregnancy until the child was age 8 years. At age 8 years, the authors administered the Behavioral Assessment System for Children-2 (BASC-2), Behavior Rating Inventory of Executive Function, and Wechsler Intelligence Scale for Children-IV. They estimated covariate-adjusted differences in composite scores from each instrument using a multiple informant model designed to identify heightened windows of vulnerability. Among all children, there was not strong evidence that the associations between BPA and neurobehavior varied by the timing of exposure (Visit x BPA p-valuesÃ¢â€°Â¥0.16). However, child sex modified the associations of repeated BPA measures with BASC-2 scores (Visit x Sex x BPA p-values=0.02-0.23). For example, each 10-fold increase in prenatal BPA was associated with more externalizing behaviors in girls (ÃŽÂ²=6.2, 95% CI: 0.8, 11.6), but not boys (ÃŽÂ²=-0.8, 95% CI: -5.0, 3.4). In contrast, a 10-fold increase in 8-year BPA was associated with more externalizing behaviors in boys (ÃŽÂ²=3.9, 95% CI: 0.6, 7.2), but not girls (ÃŽÂ²=0.3, 95% CI: -3.5, 4.1). CONCLUSIONS: Sex-dependent associations between BPA and child neurobehavior may depend on the timing of BPA exposure.