Neurodevelopmental outcomes of seychellois children from the pilot cohort at 108 months following prenatal exposure to methylmercury from a maternal fish diet

The Seychelles Child Development Study has been unable to confirm any relat ionship between maternal exposure to MeHg during pregnancy and adverse deve lopmental outcomes. In this report, 87 children from a pilot cohort were ev aluated at 9 years of age. Each child was given a battery testing specific cognitive, visual motor, and motor skills using standardized psychometric a nd neuro-psychological tests. The results indicated no adverse association between maternal MeHg exposure and any developmental outcome measure. For t hree endpoints (Boston Naming Test and two tests of visual motor coordinati on), enhanced performance in males was associated with increasing prenatal MeHg exposure. A secondary analysis including both prenatal MeHg and postna tal MeHg exposure was done even though we lacked postnatal hair for about 3 5% of the cohort. The results of the secondary analysis mirrored the outcom es of the primary analysis regarding prenatal exposure but were less robust . The results of this study are consistent with earlier findings from the 6 6-month evaluations of the SCDS Main cohort. Since MeHg is neurotoxic, this effect is likely due to other factors associated with consumption of fish. (C) 2000 Academic Press.