Prenatal exposure to heavy metals: effect on childhood cognitive skills and health status.

Prenatal exposure to seven heavy metals (cadmium, chromium, cobalt, lead, mercury, nickel, and silver) was determined for amniotic fluid taken from 92 pregnant women undergoing amniocentesis at approximately 16 to 18 weeks' gestation. Follow-up assessment of their children's cognitive skills and health status was conducted when the children were approximately 3 years of age. The presence of these metals co-occurred in amniotic fluid. A prenatal toxic risk score was derived which was a weighted score reflecting the presence of the various metals in amniotic fluid. The toxic risk score was negatively related to performance on the McCarthy Scales of Children's Abilities and positively related to the number of child illnesses reported. These results suggest the need for further prospective research on the adverse effects of prenatal exposure to various metals in combination.