Prenatal perfluoroalkyl substances exposure and neurodevelopment in toddlers: Findings from SMBCS

Background: Prenatal perfluoroalkyl substances (PFAS) exposure has been reported to affect offspring neuro-development, while epidemiological evidences were limited and inconsistent.Objectives: We aimed to evaluate the associations between cord serum PFAS concentrations and neuro-development in toddlers from 1 to 3 years of age.Methods: A total of 716 children from Sheyang Mini Birth Cohort Study (SMBCS) were included in this study. 12 PFAS concentrations were quantified in cord serum. Neurodevelopment was assessed using the Developmental Screen Test for Children Aged 0-6 Years at 1 year and the Gesell Developmental Schedules (GDS) at 2 and 3 years, respectively. Development quotient (DQ) z-score was standardized from DQ to eliminate the difference caused by two methods. We used generalized linear model (GLM) and Bayesian kernel machine regression (BKMR) to explore the associations of single or mixture PFAS exposure with neurodevelopment measurements at each time point. Associations between PFAS exposure and longitudinal changes in DQ z-score were investigated through generalized estimating equation (GEE) and trajectory analysis.Results: In general, prenatal PFAS concentrations showed negative associations with neurodevelopment mea-surements at specific age. When accounting for longitudinal changes from 1 to 3 years of age, PFOA was negatively associated with DQ z-score (8 =-0.212, 95% CI:-0.422,-0.003), the association was only found significant in boys after stratified by gender (8 =-0.327, 95% CI:-0.616,-0.038). Meanwhile, increased PFBS (OR = 2.159, 95% CI: 1.177, 3.959) and PFHpA (OR = 1.700, 95% CI: 1.016, 2.846) exposure was associated with elevated odds for the low-score trajectory group. The results of mixture of PFAS further confirmed above findings.Conclusions: Our findings suggested that prenatal PFAS exposure may be associated with adverse neuro-development effects in the first 3 years of life. Further studies are warranted to confirm our findings.