Prenatal PFAS exposure and early childhood sleep quality in the ECHO Cohort.

Per- and polyfluoroalkyl substances (PFAS) are persistent endocrine-disrupting chemicals that readily cross the placenta and may interfere with hormonal systems essential for neurodevelopment and circadian regulation. We examined associations between prenatal exposure to individual PFAS and early childhood sleep quality. The analytic sample included 2836 mother-child pairs from 14 study sites in the Environmental influences on Child Health Outcomes (ECHO) Cohort. We assessed Child Behavior Checklist (CBCL) Sleep Problems T-scores from ages 1-5 years. Maternal serum concentrations of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS) were measured during pregnancy. Linear mixed-effects models with random intercepts estimated associations between log2-transformed PFAS concentrations and CBCL scores, with covariate adjustment. The mean maternal age was 29.6 years, and the sample was racially and socioeconomically diverse (43% non-Hispanic White, 24% Black, and 23% Hispanic; 27% holding advanced degrees; and 36% reporting annual incomes <$30,000). In adjusted analyses, higher prenatal PFOA concentrations were associated with higher CBCL sleep problem scores in early childhood (β = 0.13; 95% CI: 0.05, 0.21). Associations for PFOS, PFNA, and PFHxS were small and not statistically significant. Although the magnitude of the observed PFOA association was modest, the findings add to a limited evidence base on prenatal PFAS exposure and parent-reported sleep-related behaviors in early childhood and warrant confirmation in future studies that incorporate harmonized trimester-specific exposure assessment, objective sleep measures, and mixture-based analytic approaches.