Zinc concentrations in maternal blood during pregnancy and post partum, in cord blood and amniotic fluid.

Zinc deficiency was reported to lead to congenital malformations and abnormal fetal development, and zinc concentration in amniotic fluid has been found to be correlated with fetal birth weight. In the present study, zinc concentrations were estimated in 8 pregnant women at 15 gestational weeks and 68 pregnant women at term. Maternal serum zinc concentration in early and term pregnancy was significantly lower than that of the non-pregnant controls (mean values +/- SEM being 9.8 +/- 0.6, 9.3 +/- 0.2, and 11.5 +/- 0.3 mumol/l, respectively). Maternal serum zinc concentrations reached the non-pregnant level by one week post partum. The mean serum zinc concentration in cord blood was 14.4 (+/- 0.4) mumol/l. The zinc concentration in the amniotic fluid was very low both in early pregnancy and at term 1.1 and 0.8 mumol/l, respectively, and no correlation was found to the birth weight. Low serum zinc content in pregnant women occurs as a normal feature and congenital malformation as a consequence of disturbed zinc metabolism is probably only to be seen in instances of extreme zinc deficiency in conjunction with malnutrition.