Zinc concentration in gravida's serum and amniotic fluid during normal pregnancy.

Zinc concentration was determined in maternal serum and amniotic fluid during normal pregnancy. The nonpregnant zinc concentration in the serum of about 110 micrograms% decreases gradually during pregnancy to about half the normal level. Amniotic fluid zinc concentration shows a slight decrease and remains nearly constant until the 34th to 36th week of gestation, and then increases sharply (statistically significant) reaching the highest level at 40-42 weeks from the last menstrual period. The maternal-fetal metabolism of zinc, the various factors effecting zinc levels in maternal serum and amniotic fluid during pregnancy have been discussed in view of our results. These may serve as data base for further studies on the role of zinc in normal and pathological human pregnancies.