Association between Maternal Lead Exposure from Seafood Consumption and Neurodevelopment: A Systematic Review

Despite the essential nutrients, maternal seafood consumption during pregnancy or lactation (PL) is also a potential source of toxins, including lead (Pb). The association between exposure to Pb from seafood during PL on children's neurodevelopment is uncertain. This systematic review assessed the association of exposure to Pb from seafood during PL on children's neurodevelopment. Embase, PubMed, CENTRAL, and PsycINFO were searched for English-language peer-reviewed articles. Two independent reviewers screened at title, abstract, and full-text levels. Experimental and observational studies comparing different levels of exposure to seafood and Pb were eligible if: 1) the exposed population included healthy pregnant or lactating individuals from high or very high human development index countries; 2) assessed neurodevelopment in children ≤18 y old; and 3) measured maternal seafood intake, Pb exposure and analyzed their relationship with each other and/or their association with child neurodevelopment. The Cochrane risk of bias in nonrandomized studies - of exposure (ROBINS-E) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tools were used to assess the risk of bias and certainty of evidence. Four included articles from 3 prospective cohort studies in Asia examined cognition, motor development, and behavior in children 12-60 mo. Only 1 study reported an analysis between seafood intake and Pb concentrations during PL, which showed a weak, nonsignificant association. Pb concentrations were not associated with child cognitive development or behavioral problems, but a weak, negative association with child motor development was reported. The certainty of the evidence was very low due to the few included studies with some or a high risk of bias. Higher seafood intake in this evidence favored positive developmental outcomes from 1 prospective cohort study, though significance varied. Overall, evidence was not available to address a direct association between Pb exposure from seafood intake during PL and child neurodevelopment. Several other limitations resulted in a very low certainty of overall evidence. This systematic review was registered at PROSPERO as CRD42023494884.