Efficacy of zinc sulfate on indirect hyperbilirubinemia in premature infants admitted to neonatal intensive care unit: a double-blind, randomized clinical trial

BACKGROUND: Hyperbilirubinemia is a common neonatal problem. Studies conducted on the effectiveness of zinc salts on serum indirect bilirubin levels in newborns have yielded different results, all calling for further research. This study aimed to determine the effect of oral zinc sulfate on indirect hyperbilirubinemia in preterm infants admitted to the neonatal intensive care unit. METHODS: A randomized double-blind clinical trial was performed in the neonatal intensive care unit of Vali-e-Asr Hospital in Birjand, Iran. The study population comprised neonates aged between 31 and 36 gestational weeks, who required phototherapy in the neonatal intensive care unit. A total of 60 neonates were selected by census and allocated into an experimental group and a control group. In addition to phototherapy, the experimental group received 1 cc/Kg zinc sulfate syrup (containing 5 mg/5 cc zinc sulfate; Merck Company, Germany), and the control group received a placebo syrup (containing 1 cc/kg sucrose). Data were analyzed in SPSS-21 software using the independent t-test, repeated-measures ANOVA, Bonferroni post-hoc test, and Mann-Whitney test. P-values smaller than 0.05 were considered significant. RESULTS: Bilirubin level changes in the experimental and control groups six hours after intervention were − 1.45 ± 3.23 and − 0.49 ± 0.37 (p = 0.024), respectively. The changes 24 and 48 h after intervention were-3.26 ± 2.78 and − 1.89 ± 1.20 (p = 0.017) in the experimental group and − 4.89 ± 2.76 and − 3.98 ± 2.32 (p = 0.23) in the control group, respectively. There was no significant difference in the phototherapy duration between the two groups (p = 0.24). CONCLUSIONS: The results of this study showed that the use of zinc sulfate syrup in preterm infants with indirect hyperbilirubinemia significantly reduced bilirubin levels within 48 h of treatment. TRIAL REGISTRATION: Trial registration: IRCT, IRCT2015120825439N1. Registered 21 February 2016, http://irct.ir/trial/21277