Maternal zinc and selenium status in pregnancies with a neural tube defect or elevated plasma alpha-fetoprotein.

Zinc and selenium status was assessed in 30 non-pregnant women, 69 women during normal pregnancy, six with a fetus with a neural tube defect (NTD) and 16 who had a raised plasma alpha-fetoprotein (AFP) but no detectable fetal abnormality. Plasma zinc and selenium concentrations were significantly reduced in the second trimester of normal pregnancy compared with non-pregnant levels. A significant decrease in concentrations of zinc in plasma and selenium in plasma and leucocytes was observed in women in the third trimester compared with women in the second trimester. Women with a fetal NTD and women with an unexplained elevation of plasma AFP had significantly lower leucocyte concentrations of zinc and of selenium. Mean values for plasma zinc, plasma and erythrocyte selenium, and for the activity of glutathione peroxidase in whole blood did not differ from those for normal pregnancy.