Neurodevelopmental outcomes at 5 years in children exposed prenatally to maternal dental amalgam: The Seychelles Child Development Nutrition Study

Limited human data are available to assess the association between prenatal mercury vapor (Hg0) exposurefrom maternal dental amalgam restorations and neurodevelopment of children. We evaluated the associationbetween maternal dental amalgam status during gestation and children's neurodevelopmental outcomes at5 years in the Seychelles Child Development Nutrition Study (SCDNS). Maternal amalgam status was determinedprospectively in a longitudinal cohort study examining the associations of prenatal exposure to nutrientsand methylmercury (MeHg) with neurodevelopment. A total of 236 mother–child pairs initially enrolled in theSCDNS in 2001 were eligible to participate. Maternal amalgamstatus was measured as number of amalgam surfaces(the primary metric) and number of occlusal points. The neurodevelopmental assessment battery wascomprised of age-appropriate tests of cognitive, language, and perceptual functions, and scholastic achievement.Linear regression analysis controlled for MeHg exposure, maternal fatty acid status, and other covariates relevantto child development. Maternal amalgam status evaluation yielded an average of 7.0 surfaces (range 0–28) and11.0 occlusal points (range 0–40) during pregnancy. Neither the number of maternal amalgam surfaces norocclusal points were associated with any outcome. Our findings do not provide evidence to support a relationshipbetween prenatal exposure to Hg0 from maternal dental amalgam and neurodevelopmental outcomes inchildren at 5 years of age.