Association of prenatal exposure to perfluoroalkyl and polyfluoroalkyl substances with fetal growth trajectories

Background: Maternal perfluoroalkyl and polyfluoroalkyl substances (PFAS) exposure during pregnancy is linked to adverse birth outcomes; however, its impact on fetal growth trajectories remains unclear. Objective: To examine the relationship between prenatal PFAS exposure and fetal growth trajectories. Methods: We included 352 mother-infant pairs from a prospective study conducted at Changsha Hospital for Maternal and Child Health Care, Hunan Province, China. Maternal blood samples at 11-13 weeks gestation were analyzed for 25 PFAS. Fetal growth indicators-estimated fetal weight (EFW), biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL)-were measured at 14-41 weeks of gestation and expressed as Z-scores using INTERGROWTH-21st standards. Linear mixed-effects models assessed associations between PFAS levels and growth trajectories, with subgroup analyses performed by infant sex. Results: Early pregnancy perfluorooctanoic acid (PFOA) concentration was negatively associated with EFW (3 = -0.17, 95% confidence interval [CI]: -0.33, -0.01) Z-scores, perfluorodecanoic acid (PFDA) concentration was negatively associated with BPD (3 = -0.13, 95% CI: -0.26, -0.002) and AC (3 = -0.12 95% CI: -0.23, -0.004) Z-scores; perfluoroundecanoic acid (PFUdA) concentration was negatively associated with EFW (3 = -0.14, 95% CI: -0.26, -0.02) and BPD (3 = -0.18, 95% CI: -0.30, -0.06) Z-scores, perfluorooctane sulfonic acid (PFOS) concentration was negatively associated with AC (3 = -0.13, 95% CI: -0.25, -0.01) Z-scores. In contrast, Nethylperfluoro-1-octanesulfonamide (N-EtFOSA-M) concentration was positively associated with EFW (3 = 0.11, 95% CI: 0.02, 0.19), BPD (3 = 0.11, 95% CI: 0.02, 0.20) and FL (3 = 0.13, 95% CI: 0.04, 0.22) Z-scores and potassium11-chloroeicosafluoro-3-oxaundecane-I-sulfonate (8:2CI-PFESA) concentration was positively associated with HC (3 = 0.08, 95% CI: 0.004, 0.16) Z-scores. Subgroup analyses revealed that PFDA, PFUdA, and perfluorotridecanoic acid (PFTrDA) concentrations were negatively associated with EFW Z-scores in female infants, and 8:2CI-PFESA concentrations was positively associated with HC and FL Z-scores in male infants. Conclusion: Legacy PFAS exposure may impede fetal growth, especially in female infants; whereas, novel PFAS may be positively associated with fetal growth, particularly in male infants.