Exposure to metals during pregnancy and neuropsychological development at the age of 4 years

• Concentrations of seven metals (cobalt, copper, arsenic, cadmium, antimony, thallium and lead) were measured at 1st and 3rd trimester of pregnancy.
• No statistically significant associations were found between metals and general cognitive scale or executive function of the MSCA.
• Prenatal exposure to metals was not associated to ADHD symptomatology at the age of 4 years.

BackgroundThere is insufficient epidemiological evidence for deciding whether prenatal exposure to the current low-levels of metals in developed countries may affect neuropsychological function in early childhood.ObjectivesOur goal was to evaluate potential neurotoxic effects of prenatal exposure to seven metals (cobalt, copper, arsenic, cadmium, antimony, thallium and lead), during the 1st and 3rd trimester of pregnancy, on child neuropsychological development at 4 years of age.Materials and methodsThis study was based on a population-based birth cohort established in Sabadell (Catalonia, Spain) as part of the INMA [Environment and Childhood] Project. Metals were measured in 485 urine samples collected from mothers during the 1st and 3rd trimester of pregnancy. We assessed the neuropsychological development of 553 4-year-olds with the McCarthy Scales of Childrens’ Abilitites (MSCA), together with their ADHD symptomatology, using the ADHD-DSM-IV criteria. A total of 385 children were included in the present study.ResultsWe found no statistically significant associations between metals and general cognitive scale or executive function of the MSCA. We found negative coefficients for the exposure to cadmium 1st trimester, cadmium 3rd trimester and lead 3rd trimester on the general cognitive score of MSCA, although these results were not significant. We did not find any association between prenatal exposure to metals and ADHD symptomatology at the age of 4 years.ConclusionsOur results do not suggest that prenatal exposure to current low-levels of metals impairs children's cognitive development during preschool years.