title: The effect of zinc supplementation on pregnancy outcome: a randomized controlled trial.
abstract: OBJECTIVE
  This study aimed to evaluate the impact of prenatal zinc supplementation on pregnancy outcomes.
  
  
  METHODS
  A randomized controlled trial with equal randomization (1:1) was conducted on 540 pregnant women in Rasht, Iran from January 2010 to January 2012. Participants were randomly assigned to receive a daily supplement including 400-µg folic acid and 30-mg ferrous sulfate, with or without 15-mg zinc sulfate from the 16th week of gestation until delivery.
  
  
  RESULTS
  Mean difference of birth weight between the two groups was not significantly different (3262 ± 390 g in the zinc, 3272 ± 403 g in the no-zinc groups) (p = 0.780). There were no significant differences between the two groups in terms of means of head circumference (p = 0.999), length (p = 0.848), and gestational age at birth (p = 0.057) incidences of low birth weight (p = 0.863), macrosomia (p = 0.642), and the Apgar score >7 at 5 min (p = 0.999), incidences of preterm delivery (p = 0.999), pre-eclampsia (p = 0.835), premature rupture of membranes (p = 0.630), and spontaneous abortion (p = 0.772). Abruption of placenta, amnionitis, stillbirth, and intrauterine death were not observed.
  
  
  CONCLUSIONS
  Based on our findings, 15-mg zinc supplementation daily from 16 weeks of pregnancy until delivery cannot improve pregnancy outcomes.
authors.affiliation: a Department of Obstetrics and Gynecology , Reproductive Health Research Center, Alzahra Hospital, Guilan University of Medical Sciences , Rasht , Iran and.
authors.forename: Ziba
authors.initials: Z
authors.lastname: Zahiri Sorouri
authors.affiliation: b Reproductive Health Research Center, Alzahra Hospital, Guilan University of Medical Sciences , Rasht , Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Sadeghi
authors.affiliation: b Reproductive Health Research Center, Alzahra Hospital, Guilan University of Medical Sciences , Rasht , Iran.
authors.forename: Davoud
authors.initials: D
authors.lastname: Pourmarzi
mesh_terms: D000328:Adult; D001724:Birth Weight / Q000187:drug effects; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007492:Iran / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology; D011256:Pregnancy Outcome / Q000453:epidemiology; D055815:Young Adult; D015032:Zinc / Q000008:administration & dosage*
chemical_list: D015032:Zinc
keywords: Birth weight; maternal outcome; neonatal outcome; zinc supplementation