Impact of early-life bisphenol A exposure on behavior and executive function in children

Abstract

Objectives: To estimate the impact of gestational and childhood bisphenol A (BPA) exposures on behavior and executive function at 3 years of age and to determine whether child gender modified those associations.

Methods: We used a prospective birth cohort of 244 mothers and their 3-year-old children from the greater Cincinnati, Ohio, area. We characterized gestational and childhood BPA exposures by using the mean BPA concentrations in maternal (16 and 26 weeks of gestation and birth) and child (1, 2, and 3 years of age) urine samples, respectively. Behavior and executive function were measured by using the Behavior Assessment System for Children 2 (BASC-2) and the Behavior Rating Inventory of Executive Function-Preschool (BRIEF-P).

Results: BPA was detected in >97% of the gestational (median: 2.0 μg/L) and childhood (median: 4.1 μg/L) urine samples. With adjustment for confounders, each 10-fold increase in gestational BPA concentrations was associated with more anxious and depressed behavior on the BASC-2 and poorer emotional control and inhibition on the BRIEF-P. The magnitude of the gestational BPA associations differed according to child gender; BASC-2 and BRIEF-P scores increased 9 to 12 points among girls, but changes were null or negative among boys. Associations between childhood BPA exposure and neurobehavior were largely null and not modified by child gender.

Conclusions: In this study, gestational BPA exposure affected behavioral and emotional regulation domains at 3 years of age, especially among girls. Clinicians may advise concerned patients to reduce their exposure to certain consumer products, but the benefits of such reductions are unclear.

FIGURE 1

Box plots of nonstandardized and creatinine-standardized urinary BPA concentrations. Creatinine-standardized urinary BPA concentrations were calculated by dividing urinary BPA concentrations by urinary creatinine concentrations, to control for urine dilution, whereas nonstandardized concentrations were not. Whiskers represent the minimum and 1.5 times the interquartile range. The tops and bottoms of the boxes represent the 75th and 25th percentiles, respectively. The lines in the boxes represent the medians, and the diamonds represent the means. Circles represent extreme observations (>1.5 times the interquartile range).

FIGURE 2

Scatterplot and adjusted smoothed regression of gestational urinary BPA concentrations and BASC-2/BRIEF-P subscale scores at 3 years of age: A, girls; B, boys. Models were adjusted for race (white, black, or other), household income (continuous, in thousands of dollars), education (graduate/professional school, bachelor's degree, some college, high school, or less than high school), marital status (married or unmarried), depressive symptoms during pregnancy (continuous), Home Observation for Measurement of the Environment scores (continuous), log₁₀-transformed mean gestational serum cotinine concentrations, and log₁₀-transformed mean gestational low molecular weight urinary phthalate concentrations. The relationship was smoothed by using a restricted, cubic, polynomial spline with knots at the 10th, 50th, and 90th percentiles of the gestational urinary BPA concentrations. Black lines represent mean regression lines, gray bands are 95% CIs, and dots are raw data.