Comparison of hyperbilirubinemia incidence between the newborns of zinc-taking and non-zinc-taking mothers during the third trimester of pregnancy

Background: Identification and control of the risk factors for hyperbilirubinemia can reduce the incidence and complications of this condition. Serum zinc level in newborns is reported to be one of the factors affecting the severity and incidence of neonatal hyperbilirubinemia. Therefore, the present study was conducted to compare hyperbilirubinemia incidence in neonates of zinc-taking and non-zinc-taking mothers.

Methods: In this observational study, we compared the incidence of hyperbilirubinemia during the first week of birth between newborns whose mothers had received zinc supplement during the third trimester of pregnancy (case group) with those whose mothers had not taken zinc supplement (control group). The checklist of newborns' conditions in both case and control groups was completed based on the obtained data regarding the infants, mothers, and laboratory findings. Data was analyzed using chi-squared test and t-test.

Results: The mean serum levels of zinc were 79.76±15 mg/dl and 70.93±15.67mg/dl in mothers who had received zinc during the third trimester and those who had not taken zinc supplement, respectively. The mean serum level of zinc in newborns who underwent phototherapy was 41.68±9.21 mg/dl, while it was 68.53±20.85 mg/dl in neonates who did not receive phototherapy. In addition, 36% of the neonates whose mothers had not received zinc required phototherapy, while only 11% of newborns whose mothers had taken zinc supplement received phototherapy.

Conclusion: Zinc consumption during the third trimester of pregnancy increased the serum zinc level in both newborns and mothers and reduced the incidence and severity of idiopathic hyperbilirubinemia requiring treatment.