Association between prenatal PFAS exposure and catch-up growth in children born with adverse outcomes: evidence from a prospective cohort study.

Prenatal PFAS exposure was associated with adverse birth outcomes (e.g., preterm birth, low birth weight, and small for gestational age), and catch-up growth (CUG) is critical for them to regain normal growth trajectories. However, the impact of prenatal PFAS exposure on CUG remains unclear. We enrolled 430 children born with adverse outcomes and monitored their length and weight at 42 days and 3, 6, 12, 18, 24, 36 months to evaluate the associations between maternal PFAS levels and CUG. We identified positive associations between prenatal PFAS exposure and CUG in length (L-CUG) and weight (W-CUG), particularly after 12 months, using both single-contaminant and mixture exposure models. For example, elevated odds ratio (OR) of W-CUG at 18 months were associated with perfluorooctane sulfonate (OR = 1.7), perfluorononanoic acid (OR = 1.9) and perfluorohexane sulfonate (PFHxS, OR = 1.7) exposure. Similarly, PFHxS exposure was associated with accelerated L-CUG at 36 months (OR = 3.1). PFAS mixture also showed positive associations with both L-CUG (OR = 2.1) and W-CUG (OR = 2.8) at 18 months. Longitudinal analyses further confirmed these associations, particularly for W-CUG, and excluding exclusively breastfed children yielded consistent results, supporting the robustness of the findings. Additionally, PFAS exposure was associated with longitudinal growth measures, corresponding to 9.8 %-19.2 % increases in weight, BMI, and their Z-scores. This is the first study to report that prenatal PFAS exposure is associated with accelerated CUG in children born with adverse outcomes, highlighting its critical role in early-life growth and subsequent health outcomes.