The Effect of Zinc Supplementation in the Prevention of Premature Rupture of Membranes Fetus in Pregnant Women at Risk: A Randomized, Double-Blind, Controlled

Abstract

Abstract: Background: Preterm premature rupture of membrane (PPROM) prior to 37 weeks' gestation is among the most common obstetrics problems, which is associated with prenatal mortality, and several maternal and neonatal complications. History of PPROM is a risk factor for recurrence. Zinc has important effect on the strength of membranes by affecting collagen [tensile] strength - a substance with immunity mechanism and antioxidant properties. Objective: This study was conducted to investigate the effect of zinc supplement on the prevention of PPROM and improvement some pregnancy outcomes in pregnant women with a history of PPROM during the second trimester and the early third trimester. Materials and methods: In this randomized, Double-blind, controlled clinical trial, 108 healthy pregnant women (at gestational age of 16-20 weeks) with a history of PPROM and singleton pregnancy with convenience method the were selected from Midwifery Clinic of Shahid Akbarabadi Hospital in Tehran, Iran, between 2014 and 2015. They were then divided in two groups, using randomized block design: placebo and zinc sulfate tablet (40 mg). In total, 92 subjects completed the study. The frequency of PPROM was regarded as primary outcome, and frequency of PROM and average gestational age at birth and average birth weight and head circumference were considered as the secondary outcomes. Data using SPSS 21 software and chi-square tests, T independent groups with a significance level of p <0/05 analyzed were The statistical analysis was intent-to-treat. Results: There was no between-groups difference in terms of demographic and pregnancy specifications. Results showed no significant between-groups (zinc versus placebo) difference (p>0.05) in terms of the frequency of preterm pregnancy (22% versus 33.3%), frequency of PPROM (4.9% versus 11.8%), frequency of PROM (14.6% versus 17.6%), average birth weight (3192.17 versus 3080.52), average gestational age at birth (38.2 weeks versus 37.2 weeks), and average head circumference at birth (34.63cm versus 34.81cm). Conclusions: According to the results, daily intake of zinc sulfate (40mg) by pregnant women with a history of PPROM does not contribute to the prevention of PPROM and PROM and improvement of average gestational age at birth and anthropometric measurements.