Effect of Phototherapy on Serum Bilirubin and Ionized Magnesium Level in Hyperbilirubinemic Neonates

Objectives: Jaundice is a main problem in the early neonatal period and it is suggested that there is a positive correlation between plasma ionized Mg levels and severity of hyperbilirubinemia in newborn. The aim of this study is to explore the association and to evaluate and interpret its clinical significance as well as to observe the effect of phototherapy on serum magnesium and bilirubin level in the cases of neonatal jaundice. Methods: A prospective study was conducted on 60 neonates in neonatology unit, pediatrics department, all of them suffering from neonatal jaundice >6-20 mg/dl serum bilirubin level. Blood samples for determination of plasma Mg (total and ionized) and serum bilirubin levels were obtained from infants in 4, 6, and 10 days, and statistical analysis was performed. Results: There was statistically significant difference in relation to ionized magnesium level before phototherapy mean±SD (0.57±0.03 mg/dl) and group after phototherapy mean±SD (0.54±0.02, p<0.05) correspondingly bilirubin level before phototherapy mean±SD (13.9±3 mg/dl) and after phototherapy (9±3.4 mg/dl, p<0.05). Conclusion: From this prospective study, it is concluded that phototherapy decrease serum Mg level as it decreases serum bilirubin level, and therefore there is a positive relation between serum bilirubin and serum Mg levels and rising of magnesium during hyperbilirubinemia may be a physiological compensatory mechanism that counter toxic effect of bilirubin.