Antenatal Zinc Supplementation

SourceLocation and Type of TrialInterventionMaternal OutcomePerinatal/Neonatal Outcome
Castillo-Duran et al230Chile; urban slum; RCTPregnant adolescents <20 wk gestation (n = 804) were administered either zinc supplementation (S) at 20 mg/d (n = 401) or placebo (P) (n = 403) until delivery.No effect of supplementation was seen on mean birth weight of the infants; however, the proportion of LBW births (<2500 g) in the S group was significantly lower than in the P group (6/249 vs 16/258, P = .036). The LBW rate and the preterm birth rate decreased by 66% and 51%, respectively, in the S group. Multiple regressions found a significant effect of maternal nutritional status (P = .011) and zinc supplementation (P = .05) on birth weight.
Dijkhuizen et al716Indonesia; rural setting; RCTWomen between 10–20 wk gestation (n = 229) were assigned to 1 of the 4 groups. All groups received iron + folate. 1 received β-carotene (n = 42), 1 was given zinc at 30 mg/d (n = 42) and 1 was given all 4 supplements (n = 42). The control group received only iron + folate (n = 38).Combination of prolonged labor and/or retained placenta, both indicative of uterine contractile dysfunction, was significantly higher in the zinc group compared to all other groups.The male infants born to the women supplemented with β-carotene + zinc + iron + folate were significantly heavier (mean weight 3.4 ± 0.3 kg) than the infants in the zinc + iron + folate group (3.0 ± 0.6 kg, P < .05) or the infants in the zinc + iron + folate group (3.1 ± 0.4 kg).
Merialdi717Peru; urban shantytown; RCTWomen receiving iron and folate (n = 242) were recruited between 10–16 wk pregnancy and randomized to receive either 25 mg zinc/d versus placebo.In addition to birth weight, growth of fetal anatomical parameters was assessed by ultrasonography.A positive effect of maternal zinc supplementation on fetal femur diaphysis growth was detected. No effect was seen on birth weight.
Osendarp et al*233Bangladesh; urban slum; PCSSee below, Osendarp et al.Infants of mothers taking zinc supplements had significantly fewer episodes of acute diarrhea (16% risk reduction, RR: 0.84; CI: 0.72–0.98; P = .037), dysentery (64% risk reduction; RR: 0.36; CI: 0.52–0.84; P = .019) and impetigo (47% risk reduction; RR: 0.53; CI: 0.34–0.82; P = .005). Impact was isolated to LBW infants.
Osendarp et al*232Bangladesh; urban slum; RCTPregnant women at 12–16 wk gestation (n = 559) were given either 30 mg/d of zinc (n = 269) or placebo (n = 290) until delivery.Supplementation had no effect on maternal pregnancy weight gain or mid upper arm circumference. There was no effect of the supplement on rates of pregnancy loss.No significant effect of treatment was observed on birth weight, gestational age, length, and head or chest circumference. No differences were observed in the rate of LBW by supplement group (RR: 1.12; CI: 0.90–1.41).
Caulfield et al718Peru; urban hospital setting; RCTPregnant women 10–24 wk gestation (n = 1295) were randomly assigned to receive either iron and folate alone or iron, folate plus 15 mg/d of zinc.No significant additional effect of the zinc supplement was seen on birth weight, or LBW or preterm delivery rates.
Garg et al719India; urban hospital setting; RCTWomen in the intervention group (n = 106) were given 45 mg/d of zinc supplement; controls (n = 62) received no supplements.Maternal supplementation significantly increased birth weight of infants (P < .001); the degree of increase was directly related to the duration of supplementation. Infants born to mothers supplemented for 6–9 mo were significantly heavier (3.45 ± 0.04 kg) than those born following supplementation for 1–3 mo (2.98 ± 0.07 kg); the mean birth weight for controls was 2.65 kg. Gestational age of supplemented babies was significantly higher than controls when given for more than 3 mo (P < .01) and was related to duration of zinc supplementation (P < .05).
  • * Data from the same trial