Prenatal Metal Exposure and Neurodevelopmental Changes in Children up to 18 Months of Age: PIPA Cohort Project, Rio de Janeiro

Early exposure to toxic metals is a growing concern due to its potential neurodevelopmental effects in children. This study investigates whether exposure to multiple metals during pregnancy influences early developmental outcomes in children aged 12–18 months living in a metropolitan setting. We conducted a prospective cohort study in Rio de Janeiro that included 393 children from PIPA project. Umbilical cord blood samples obtained at birth were processed using ICP-MS (Inductively Coupled Plasma Mass Spectrometry) to quantify metals (arsenic, lead and mercury). The children’s neurodevelopment was assessed with the Denver-II tool. We applied logistic regression analyses to explore the relationship between metal concentrations and developmental outcomes, controlling for possible confounding variables. Higher prenatal arsenic levels were linked to poorer gross motor performance, both in continuous models (OR = 1.65; 95% CI: 1.09–2.51) and in subjects with concentrations above the 95th percentile (OR = 8.84; 95% CI: 2.40–32.61), this was consistent across multi-metal models. A negative relationship between Pb concentrations and gross motor delays was observed, with an estimated Odds Ratio of 0.49 (95% CI: 0.24–0.98). Hg exposure demonstrated no association with neurodevelopment in any model. However, the lack of postnatal arsenic exposure data limits the distinction between prenatal and early childhood effects. These findings underscore the need for the continued monitoring and investigation of combined metal exposures during pregnancy. Future studies integrating prenatal and postnatal exposure assessments are warranted.