Prenatal Bisphenol A Exposure and Brain Structure in Preschool-Aged Children

Abstract

Background/Aim: In Canada, over 90% of the population has detectable levels of bisphenol A (BPA) due to dietary and non-dietary exposure. Human epidemiological studies have demonstrated behavioral effects of BPA exposure in children. Further, reported effects have been found to be sex-specific. Although behavioral outcomes have been examined, there is limited understanding of the effects of BPA exposure on children’s brain structure. This study examined the effects of maternal BPA exposure on subsequent child white matter brain structure at 3 to 6 years of age.Method: Maternal total BPA concentrations in spot urine samples obtained during the second trimester of pregnancy were analyzed for 99 women. Their children participated in magnetic resonance imaging (MRI) between 3 to 6 years of age. Associations between prenatal BPA exposure and child fractional anisotropy and mean diffusivity within 10 isolated white matter tracts were investigated, controlling for sex and total maternal creatinine levels. Anisotropy and diffusivity provide measures of white matter structure and maturity.Results: Significant positive associations were observed between the level of prenatal BPA exposure and child white matter mean diffusivity within the splenium, and the right inferior frontal occipital, inferior longitudinal fasciculus, uncinated fasciculi, and pyramidal fibers. Significant sex differences were found, with more associations noted among females. No associations were observed between prenatal BPA exposure and child white matter anisotropy.Conclusions: Higher prenatal BPA exposure was related to higher mean diffusivity in white matter tracts at 3 to 6 years of age. Developmental studies show that with age, white matter anisotropy increases and diffusivity decreases in typically developing children. The current findings suggest that exposure to higher levels of BPA prenatally may be related to reduced white matter maturity in preschool aged children.