Association of placental concentrations of phenolic endocrine disrupting chemicals with cognitive functioning in preschool children from the Environment and Childhood (INMA) Project

Abstract

Aim: To examine the association of placental concentrations of several phenolic endocrine disrupting chemicals (EDCs), including bisphenol A (BPA), parabens (PBs), and benzophenones (BzPs), with cognitive development in preschool children from the Environment and Childhood (INMA) Project in Spain. Methods: Concentrations of BPA, four PBs (methylparaben [MePB], ethylparaben [EtPB], propylparaben [PrPB], and butylparaben [BuPB]), and six BzPs (BzP-1, BzP-2, BzP-3, BzP-6, BzP-8, and 4-hydroxybenzophenone [4-OH-BzP]) were measured in placenta samples randomly selected from five INMA cohorts collected between 2000 and 2008. Neuropsychological assessment of cognitive and motor function was performed with the McCarthy Scales of Children’s Abilities (MSCA) at the age of 4-5 years. Associations were assessed in a sub-sample of 191 mother-child pairs using linear and logistic regression models adjusted for confounding factors. Results: PB compounds were detected in >71% of placentas, BPA in 62%, 4-OH-BzP in 50%, and the remaining BzPs in <9%. After adjustment for confounders, BPA was associated with greater odds of scoring lower (<20th percentile) in the verbal area (odds ratio [OR]= 2.78, 95% confidence interval [CI]=1.00; 5.81 for upper vs. first tertile, p-trend=0.05), whereas PrPB was inversely associated with scores in memory (β=-4.96, 95%CI=-9.54; -0.31 for detected vs. undetected), span memory (OR=2.50, 95%CI=0.95; 6.92 and 2.71, 95%CI=0.97; 6.64, respectively for middle and upper tertiles, p-trend=0.03), and motor function (β=-5.15, 95%CI=-9.26; -0.01 for upper vs. first tertile, p-trend=0.04). EtPB and total PB concentrations (∑PBs) in the middle tertile were also inversely associated with visual function of posterior cortex and quantitative scores, respectively, but linear trends were not statistically significant. Conclusions: These associations of BPA and PrPB with poorer verbal, memory, and motor skills are novel observations that warrant further attention. Larger prospective studies are required to confirm whether prenatal exposure to BPA and other phenols is associated with impaired cognitive development.