Efficacy of Zinc in Reducing Hyperbilirubinemia Among High Risk Neonates - A Double Blind Randomized Trial

Neonatal hyperbilirubinemia is a common problem occurring in nearly 5-25% neonates.Inhibition of enterohepatic circulation is one of the therapies being tried for neonatal jaundice. Studies have suggested that in a neonate, the postulated enterohepatic pathway is of a magnitude that could be significant in the overall body economy of bilirubin.Zinc has also been investigated for its role in decreasing the STB levels by inhibiting enterohepatic circulation. There have been animal studies which have investigated the role of zinc in decreasing the serum bilirubin levels. The mechanism proposed is that zinc salts precipitate Unconjugated bilirubin from unsaturated micellar solution of bile salts and consequently inhibit the enterohepatic circulation of bilirubin. This is the first study to evaluate the role of zinc in neonatal jaundice.

Study Design: In this randomized placebo controlled clinical trial neonates born at ≥35 wk of gestation and with total serum bilirubin ≥6mg% were given either zinc gluconate (n = 148) or placebo (n = 146) in a dose of 10mg per day between days 2 and 7 of life. Jaundice was assessed clinically and total serum bilirubin estimated using spectrophotometry. Infants were followed up clinically until discharge and then again at day 7 of life. Hyperbilirubinemia was defined as total serum bilirubin ≥15mg%.

Results: Incidence of hyperbilirubinemia was comparable in zinc and placebo groups (OR 0.95, 95% CI 0.50-1.67, p=0.92). The requirement of phototherapy was similar in the two groups (OR 0.81, 95% CI 0.41-1.61, p=0.55). The mean hours of phototherapy in the zinc group were also similar in the two groups (p=0.63). No significant difference with respect to mean levels of bilirubin (mg/dL) at 72±12 hours of age was observed in two groups(zinc 11.3±3.3,placebo 11.5±3.8,p=0.63). No significant adverse effects of zinc were noted.

Conclusion: Twice daily zinc administration in a dose of 10 mg/day does not reduce hyperbilirubinemia in at risk neonates in the first week of life.

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Inclusion criteria

• Neonates born at ≥35 weeks gestation and with total serum bilirubin ≥ 6 mg/dL at 24±6 h of life.

Exclusion criteria

• Rh incompatibility
• Those given exchange transfusion/ phototherapy within 24 h of age.
• Major gross congenital anomaly
• Anticipated to require neonatal intensive care or required neonatal intensive care for more than 24 h.
• Systemic sepsis