Associations between maternal exposure to perfluoroalkylated substances (PFASs) and infant birth weight: a meta-analysis

The objective of this study was to determine the associations between maternal exposure to PFASs and infant birth weight and to explore evidence for a possible dose-response relationship. Four databases including PubMed, Embase, Web of Science, and Medline before 20 September 2022 were systematically searched. A fixed-effect model was used to estimate the change in infant birth weight (g) associated with PFAS concentrations increasing by 10-fold. Dose-response meta-analyses were also conducted when possible. The study follows the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A total of 21 studies were included. Among these studies, 18 studies examined the associations between PFOA and birth weight, 17 studies reported PFOS, and 11 studies discussed PFHxS. Associations between PFHxS (ES = −5.67, 95% CI: −33.92 to 22.59, P = 0.694) were weaker than those for PFOA and PFOS (ES = −58.62, 95% CI: −85.23 to −32.01, P < 0.001 for PFOA; ES = −54.75, 95% CI: −84.48 to −25.02, P < 0.001 for PFOS). The association was significantly stronger in the high median PFOS concentration group (ES = −107.23, 95% CI: −171.07 to −43.39, P < 0.001) than the lower one (ES = −29.15, 95% CI: −63.60 to −5.30, P = 0.097; meta-regression, P = 0.045). Limited evidence of a dose-response relationship was found. This study showed negative associations between maternal exposure to PFASs and infant birth weight. Limited evidence of a dose-response relationship between exposure to PFOS and infant birth weight was found. Further studies are needed to find more evidence.