The PIPA Project is a prospective birth cohort study based in Rio de Janeiro, Brazil, whose pilot study was carried out between October 2017 and August 2018. Arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) concentrations were determined in maternal (n = 49) and umbilical cord blood (n = 46). The Denver Developmental Screening Test II (DDST-II) was applied in 50 six-month-old infants. Metals were detected in 100% of the mother and newborn samples above the limits of detection. Maternal blood lead concentrations were higher in premature newborns (GM: 5.72 µg/dL; p = 0.05). One-third of the infants (n = 17–35.4%) exhibited at least one fail in the neurodevelopment evaluation (fail group). Maternal blood arsenic concentrations were significantly (p = 0.03) higher in the “fail group” (GM: 11.85 µg/L) compared to infants who did not fail (not fail group) (GM: 8.47 µg/L). Maternal and umbilical cord blood arsenic concentrations were higher in all Denver Test’s domains in the “fail group”, albeit non-statistically significant, showing a tendency for the gross motor domain and maternal blood (p = 0.07). These findings indicate the need to further investigate the toxic effects of prenatal exposure to metals on infant neurodevelopment.

The PIPA Project is a prospective birth cohort study based in Rio de Janeiro, Brazil, whose pilot study was carried out between October 2017 and August 2018. Arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) concentrations were determined in maternal (n = 49) and umbilical cord blood (n = 46). The Denver Developmental Screening Test II (DDST-II) was applied in 50 six-month-old infants. Metals were detected in 100% of the mother and newborn samples above the limits of detection. Maternal blood lead concentrations were higher in premature newborns (GM: 5.72 µg/dL; p = 0.05). One-third of the infants (17–33%) exhibited at least one fail in the neurodevelopment evaluation (fail group). Maternal blood arsenic concentrations were significantly (p = 0.02) higher in the "fail group" (GM: 11.85 µg /L) compared to infants who did not fail (not fail group) (GM: 8.46 µg /L). Maternal and umbilical cord blood arsenic concentrations were higher in all Denver Test’s domains (except personal/social) in the “fail group”, albeit non-statistically significant. These findings indicate the need to further investigate the toxic effects of prenatal exposure to metals on infant neurodevelopment.

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.