Prenatal environmental chemical exposures and longitudinal patterns of child neurobehavior

Prenatal chemical exposures may adversely affect neurodevelopment, but few studies have examined the persistence of these associations. We examined whether associations between prenatal bisphenol A (BPA) or polybrominated diphenyl ether (PBDE) exposures persist or resolve as children age.

We followed 346 mother-child pairs (enrolled 2003-2006) from Cincinnati, OH from pregnancy until children were 8 years old. We measured BPA in urine collected at 16 and 26 weeks gestation and PBDE-47 in serum collected at 16 weeks gestation. We administered repeated measures of children's behavior, mental/psychomotor development, and IQ from ages 1-8 years. We determined if associations of BPA or PBDE-47 with child neurobehavior persisted or resolved as children aged using linear mixed models and estimated neurobehavioral measure reproducibility using intraclass correlation coefficients (ICCs).

Higher BPA in girls and higher PBDE-47 in both boys and girls were associated with more externalizing behaviors; these associations persisted from ages 2-8 years (exposure×age interaction p-values≥0.36). Higher PBDE-47 concentrations were associated with decreases in MDI from ages 1-3 years (PBDE-47x age interaction p-value=0.03) and persistently lower IQ at ages 5 and 8 years (PBDE-47×age interaction p-value=0.56). Mental/psychomotor abilities had fair reproducibility from ages 1-3 years (ICCs∼0.4), cognitive abilities from ages 5 to 8 years had excellent reproducibility (ICCs=0.7-0.8), and parent-reported behaviors from ages 2-8 years had poor to good reproducibility (ICCs=0.38-0.59).

Prenatal BPA and PBDE-47 concentrations were persistently associated with more externalizing behaviors. PBDE-47 concentrations were inversely associated with cognitive abilities that strengthened over time.