Evaluation of serum zinc-binding capacity during childbirth, in newborn infants and during the menstrual cycle

Abstract

This is a study of the value of total serum zinc, serum zinc per g of protein, serum zinc-binding capacity and serum zinc-binding capacity per g of protein in 102 pregnant women during childbirth and in the cord blood of their newborn infants. A control group is established by analyzing these parameters in 10 healthy non-pregnant women on the first day of menstruation and on the day of ovulation during two consecutive menstrual cycles. The total serum zinc and serum zinc per g of protein values found were significantly higher in cord blood than in maternal blood, and the binding capacity of zinc and of zinc per g protein were significantly higher in maternal blood. There is a negative correlation between total zinc and binding capacity and total zinc and binding capacity per g protein both in maternal and in cord blood. In the control group, the values of total zinc and zinc per g protein vary from one menstrual cycle to the next and between the different phases of each cycle. Zinc-binding capacity per g protein during ovulation is significantly lower than during menstruation. These results allow us to conclude that the rise of zinc-binding capacity and zinc-binding capacity per g protein in maternal blood during childbirth, and during menstruation in the control group, can be due to the effect of progesterone. The fact that zinc-binding capacity and zinc-binding capacity per g of protein are higher in maternal blood than in cord blood would confirm the existence of mechanisms which tend to increase binding of zinc in the fetus.