Prenatal exposure to methylmercury and LCPUFA in relation to birth weight

BackgroundEpidemiologic studies have been inconclusive regarding the impact of coexposure to long chain polyunsaturated fatty acids (LCPUFA) and methylmercury (MeHg) from fish consumption during pregnancy on measures of fetal development.ObjectivesWe evaluated the association between birth weight and prenatal maternal LCPUFA status and MeHg exposure in the Republic of Seychelles.MethodsWe measured LCPUFA in maternal whole blood collected at 28 weeks of gestation and following delivery and MeHg in maternal hair obtained at delivery. There were 230 births with complete data on birth weight and covariates. Multiple linear regression models controlled for infant sex, gestational age, maternal age, smoking during pregnancy, intrapartum weight gain, prepregnancy body mass index, maternal socioeconomic status, parity, gestational diabetes, and alcohol use during pregnancy.ResultsThe average birth weight was 3252 g (range 1654–4450) and the average gestational age was 39 weeks (range 34–41). Prenatal MeHg exposure and maternal LCPUFA status were not associated with birth weight. Infant sex and length of gestation were the only predictors, with male sex and increased gestational age consistently associated with greater birth weight.ConclusionsThese findings do not support a relationship between prenatal exposure to LCPUFA and/or MeHg from fish consumption and birth weight.