Scholastic achievement among children enrolled in the Seychelles Child Development Study.

The Seychelles Child Development Study is a longitudinal cohort study following a group of 779 children exposed prenatally to methyl mercury (MeHg) through a maternal diet high in fish. The cohort has been examined six times beginning in infancy with no consistent evidence of adverse effects. In fact, their performance resembles what would be expected from normal children of comparable ages growing up in western cultures.

Association between prenatal dietary methyl mercury exposure and developmental outcomes on acquisition of articulatory-phonologic skills in children in the Republic of Seychelles.

Methyl mercury (MeHg) is a neurotoxicant that with sufficient exposure can seriously impair the central nervous system and cause mental retardation, cerebral palsy, and neuromotor dysfunction. The level of exposure needed to adversely affect the nervous system is unknown. Human exposure to low levels of MeHg is common from consumption of fish.

Maternal PUFA status but not prenatal methylmercury exposure is associated with children's language functions at age five years in the Seychelles.

Evidence from the Seychelles Child Development Nutrition Study suggests that maternal nutritional status can modulate the relationship between prenatal methylmercury (MeHg) exposure and developmental outcomes in children. The aim of this study was to investigate whether maternal PUFA status was a confounding factor in any possible associations between prenatal MeHg exposure and developmental outcomes at 5 y of age in the Republic of Seychelles. Maternal status of (n-3) and (n-6) PUFA were measured in serum collected at 28 wk gestation and delivery.

Fish consumption, mercury exposure, and their associations with scholastic achievement in the Seychelles Child Development Study.

Studies of neurodevelopmental outcomes in offspring exposed to MeHg from maternal consumption of fish have primarily measured cognitive abilities. Reported associations have been subtle and in both adverse and beneficial directions. Changes in functional outcomes such as school achievement and behavior in exposed children and adolescents have not been examined.

Associations of maternal long-chain polyunsaturated fatty acids, methyl mercury, and infant development in the Seychelles Child Development Nutrition Study.

Fish consumption during gestation can provide the fetus with long-chain polyunsaturated fatty acids (LCPUFA) and other nutrients essential for growth and development of the brain. However, fish consumption also exposes the fetus to the neurotoxicant, methyl mercury (MeHg). We studied the association between these fetal exposures and early child development in the Seychelles Child Development Nutrition Study (SCDNS).

Neurodevelopmental effects of maternal nutritional status and exposure to methylmercury from eating fish during pregnancy.

Fish contain nutrients that promote optimal brain growth and development but also contain methylmercury (MeHg) that can have toxic effects. The present study tested the hypothesis that the intake of selected nutrients in fish or measures of maternal nutritional status may represent important confounders when estimating the effects of prenatal methylmercury exposure on child development. The study took place in the Republic of Seychelles, an Indian Ocean archipelago where fish consumption is high.

Association between prenatal exposure to methylmercury and visuospatial ability at 10.7 years in the seychelles child development study.

The Seychelles Child Development Study was designed to test the hypothesis that prenatal exposure to MeHg from maternal consumption of a diet high in fish is detrimental to child neurodevelopment. To date, no consistent pattern of adverse associations between prenatal exposure and children's development has appeared. In a comprehensive review of developmental studies involving MeHg, a panel of experts recommended a more consistent use of the same endpoints across studies to facilitate comparisons.

Is susceptibility to prenatal methylmercury exposure from fish consumption non-homogeneous? Tree-structured analysis for the Seychelles Child Development Study.

Studies of the association between prenatal methylmercury exposure from maternal fish consumption during pregnancy and neurodevelopmental test scores in the Seychelles Child Development Study have found no consistent pattern of associations through age 9 years. The analyses for the most recent 9-year data examined the population effects of prenatal exposure, but did not address the possibility of non-homogeneous susceptibility. This paper presents a regression tree approach: covariate effects are treated non-linearly and non-additively and non-homogeneous effects of prenatal methylmercury exposure are permitted among the covariate clusters identified by the regression tree.

Methylmercury and neurodevelopment: longitudinal analysis of the Seychelles child development cohort.

Background: The Seychelles Child Development Study (SCDS) has been longitudinally following a cohort of over 700 children enrolled in 1989. Their mothers consumed a diet high in fish during pregnancy. Repeated examination of the SCDS cohort at six different ages through age 11 years has shown no pattern of adverse effects.

Development and validation of a test battery to assess subtle neurodevelopmental differences in children.

There is increasing concern over the impact of low-dose exposures to environmental chemicals on children's neurobehavioral function. To determine subtle alterations in children's function, it is necessary to move beyond global measures such as IQ and employ tests that can detect small, subtle neurodevelopmental effects across a broad array of behavioral domains. We investigated the sensitivity and specificity of a battery of 63 neurodevelopmental tests or tasks designed to detect outcomes representing the type of subtle neurodevelopmental deficits caused by exposure to neurotoxicants in school-aged children.

Exploring nonlinear association between prenatal methylmercury exposure from fish consumption and child development: evaluation of the Seychelles Child Development Study nine-year data using semiparametric additive models.

Studies of the association between prenatal methylmercury exposure from maternal fish consumption and neurodevelopmental test scores in the Seychelles Child Development Study have not found adverse effects through age 9 years. The analysis for the most recent 9-year data (Lancet 361 (2003) 1686) employed conventional linear regression models. In this study we reanalyzed the same Seychelles 9-year data using semiparametric additive models with different degrees of smoothing to explore whether nonlinear effects of prenatal exposure were present.

Using measurement error models to assess effects of prenatal and postnatal methylmercury exposure in the Seychelles Child Development Study.

Studies of the effects of environmental exposures on human health typically require estimation of both exposure and outcome. Standard methods for the assessment of the association between exposure and outcome include multiple linear regression analysis, which assumes that the outcome variable is observed with error, while the levels of exposure and other explanatory variables are measured with complete accuracy, so that there is no deviation of the measured from the actual value. The term measurement error in this discussion refers to the difference between the actual or true level and the value that is actually observed.

Prenatal methylmercury exposure from ocean fish consumption in the Seychelles child development study.

Introduction: Exposure to methylmercury (MeHg) before birth can adversely affect children's neurodevelopment. The most common form of prenatal exposure is maternal fish consumption, but whether such exposure harms the fetus is unknown. We aimed to identify adverse neurodevelopmental effects in a fish-consuming population.