The National WIC Evaluation: evaluation of the Special Supplemental Food Program for Women, Infants, and Children. V. Longitudinal study of pregnant women.

The major associations with the Special Supplemental Food Program for Women, Infants, and Children (WIC) in pregnancy were increased intake of protein, iron, calcium, and vitamin C (four of five targeted nutrients) and of energy, magnesium, phosphorus, thiamin, riboflavin, niacin, vitamin B-6, and vitamin B-12; reversal of low weight gain in early pregnancy; smaller fat stores in late pregnancy; reduced frequency of premature rupture of the uterine membranes; larger infant head circumference with no effect on birth weight and length; increased birth weight and head circumference with better program quality; and lower fetal mortality of appreciable but not significant magnitude. Incremental energy intake was comparable to that in most small-scale supplementation trials. There was no evidence of effects on frequency of prenatal care, use of alcohol or tobacco, the intention to breast-feed, or the rate of breast-feeding. Maternal alcohol intake was associated with depressed infant head circumference, over and above effects on birth weight and length.