Zinc and copper nutrition in human pregnancy: a longitudinal study in normal primigravidae and in primigravidae at risk of delivering a growth retarded baby.

A longitudinal study of plasma zinc and copper concentration and plasma volume was carried out in 33 normal healthy primigravidae for comparison with 31 primigravidae selected as being at risk of delivering a growth retarded baby. Neither group received mineral or vitamin supplements. In Group A, plasma zinc concentration fell as plasma volume increased between 14 weeks and 35 weeks. Intravascular mass of zinc therefore increased and showed significant correlation with intravascular mass of albumin. Both of these were significantly lower in Group B, reflecting poorer plasma volume expansion. Plasma copper concentration mirrored the increase in plasma ceruloplasmin and was comparable in both groups. Plasma zinc and copper concentrations were unaffected by smoking or by method of feeding and there was no correlation found with percentile birth weight distribution. In both groups at 30 weeks daily dietary zinc intake was approximately half the Recommended Dietary Allowance.