Associations between prenatal exposure to perfluoroalkyl substances and neurobehavioral development in infants: A cohort study

Background  Perfluoroalkyl substances (PFASs) are persistent pollutants. These substances can be detected in pregnant women's blood and amniotic fluid, suggesting that offspring are exposed to PFASs during the fetal period. The associations between maternal PFASs exposure and neurobehavioral development in children are inconclusive.

Objective  To examine the associations between maternal PFASs exposure during pregnancy and neurobehavioral development in infants.

Methods  A total of 646 mother-infant pairs were included in the present study, based on the Shanghai-Minhang Birth Cohort Study which was conducted between April and December 2012 at the Maternal and Child Health Hospital of Minhang District in Shanghai. Eleven PFASs in pregnant women's blood (gestational 12-16 weeks), including perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUdA), perfluorododecanoic acid (PFDoA), perfluorotridecanoic acid (PFTrDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA), and perfluorodecane sulfonate (PFDS), were quantified by high performance liquid chromatography coupled with tandem mass spectrometry. When the infants turned 6 months old, their parents or other caregivers were asked to complete the Ages and Stages Questionnaires (ASQ-3) to assess neurobehavioral development of their children at a home visit. Poisson regression model with robust variance estimates was used to examine the associations between maternal PFASs concentrations and each developmental problems/delay subscale of the ASQ-3.

Results  The positive rates of eight PFASs in the 646 pregnant women exceeded 85%. The highest concentration was found in PFOA and followed by PFOS, with the median concentrations of 19.76 μg·L^-1 and 10.67 μg·L^-1, respectively. Concentrations of PFOS, PFSA (PFHxS and PFOS), and ∑PFASs (after natural log transformation) tended to be positively associated with developmental problems/delay in the fine motor subscale (per natural log unit increase:aRR_PFOS=1.60, 95% CI:1.03-2.48; aRR_PFSA=1.90, 95% CI:1.19-3.04; aRR_∑PFASs=2.11, 95% CI:1.16-3.83). The infants' sex stratified analysis results showed that in the 6-month-old girls stratum, the positive associations between the concentrations of PFOS, PFSA, and ∑PFASs and the risk of developmental problems/delay in the fine motor and problem-solving subscales were statistically significant:aRR_PFOS (95% CI) was 2.89 (1.50-5.58), aRR_PFSA (95% CI) was 4.10 (2.00-8.40), and aRR_∑PFASs (95% CI) was 3.37 (1.37-8.30) for the fine motor subscale; aRR_PFOS (95%CI) was 1.82 (1.06-3.13), aRR_PFSA (95%CI) was 2.22 (1.17-4.23), and aRR_∑PFASs (95%CI) was 2.25 (1.07-4.73) for the problem-solving subscale. No statistically significant associations were found in the 6-month-old boys stratum.

Conclusion  Maternal exposure to PFASs during pregnancy tends to increase the risk of developmental problems/delay in the fine motor and problem-solving subscales in 6-month-old girls.