MAIN NEURODEVELOPMENTAL STUDY OF SEYCHELLOIS CHILDREN FOLLOWING IN-UTERO EXPOSURE TO METHYLMERCURY FROM A MATERNAL FISH DIET - OUTCOME AT 6MONTHS

Methylmercury (MeHg) is a human neurotoxin to which the developing fet al bra in is especially sensitive. The lowest dose of MeHg that impair s neurodevelopment in the human fetus is not known. The Seychelles Chi ld Development Study (SCDS) is testing the hypothesis that fetal MeHg exposure from a maternal diet high in oceanic fish is related to child neurodevelopmental outcomes. Fish is the major protein source in the Republic of Seychelles, where a cohort of 779 mother-infant pairs was enrolled in a prospective longitudinal study. Maternal total hair merc ury values during pregnancy were determined by cold vapor atomic absor ption and ranged from 0.5 ppm to 26.7 ppm with a median of 5.9 ppm. Wh en the children were 6 1/2 months of age, an examiner blinded to the m aternal mercury value performed a neurological examination, the Fagan test of visual recognition memory, and the Denver Developmental Screen ing Test-Revised (DDST-R). On the DDST-R 2% scored other than normal w hile 3.4% had an overall neurological score other than normal. The Fag an test of visual recognition memory showed a median score of 60.5%, a nd the Rose attention measure from that test showed a median score of 37.9. The association between fetal mercury exposure and neurodevelopm ental endpoints was examined by multiple regression analyses. After ad justing for covariates, no association between the maternal hair mercu ry level during pregnancy and an adverse neurodevelopmental outcome of the child was identified at 6 1/2 months of age. (C) 1995 Intox Press , Inc.