Multimatrix Biomonitoring and Transplacental Transfer of Legacy and Emerging PFAS in Korean Pregnant Women

Abstract Maternal–fetal exposure to per- and polyfluoroalkyl substances (PFAS) cannot be adequately characterized using single biological matrices because compound-specific distribution patterns vary according to physicochemical properties and elimination pathways. We measured 33 legacy, precursor, and emerging PFAS in maternal serum, plasma, urine, and cord serum from Korean singleton pregnancies (n = 151) to characterize matrix-specific exposure profiles, transplacental transfer, and associations with maternal and neonatal factors. Matrix-specific detection patterns distinguished predominantly protein-bound PFAS detected in blood matrices from short-chain, renally excreted PFAS prevalent in urine at the population level. Notably, the precursor 6:2 diPAP showed a relatively high estimated maternal–cord concentration ratio, whereas the alternative PFAS 9Cl-PF3ONS was consistently detected in maternal blood and cord serum, suggesting compound-specific distribution patterns compared with regulated legacy PFAS. Associations with fetal growth indicators were modest, matrix- and sex-specific, and interpreted as exploratory. Overall, these findings suggest that multimatrix biomonitoring can reveal matrix-specific PFAS detection and distribution patterns that may not be captured by single-matrix approaches. However, maternal–cord comparisons should be interpreted cautiously because maternal samples were collected during pregnancy rather than at delivery.