Effects of Zinc Supplementation of Rural Pregnant Women on the Growth of Offspring in Early Childhood

PURPOSE: To explore whether zinc supplementation to rural pregnant women can improve the growth and development of their offspring during early childhood. METHODS: The effects of zinc supplementation were assessed in a double-blinded randomized control design. One hundred sixty rural pregnant women were randomly divided into four groups with 40 subjects in each.Subjects received a daily oral intake of 5 mg (group A),10 mg (group B),30 mg (group C) of zinc supplementation or placebo from the first visit to the prenatal clinic (less than 12 week of gestation) till delivery.Their children's physical,intellectual and behavioral development were assessed during 3-5 years of age.Children's anthropometrical measurements were adjusted for sex and age.Thus standardized values,Z-scores were calculated to indicate children's physical development. RESULTS: Z-scores for head circumference in group A,B and C were greater than that in the placebo group,but only the head Z-score in group C was significantly higher than that in the placebo group by 0.73 (95%CI:0.004-1.44). When all pregnant women receiving zinc supplementation (namely group A,B and C) were combined as a single group (combined group), the head Z-score in the combined group was still greater than that in the placebo group by 0.50 (95%CI:0.01-0.99). Children's intelligence quotients in three zinc supplementation groups were higher than that in the placebo group,although statistical significance and dose-effect relationship were not found, intelligence quotient for the combined group was significantly higher than that in the placebo group by 4.72 (95%CI:0.26-9.20). No statistical significances were found in weight,height, sitting height, body-mass index as well as adaptive developmental quotient between zinc supplementation groups and the placebo group. COCLUSIONS: Oral intake of daily 5-30 mg zinc supplementation to rural pregnant women who had an imbalanced diet mainly containing vegetal food could improve the development of their children's head circumference and intelligence, but had no significant effect on the development of children's weight, height, sitting height and adaptive developmental quotient.