Effect of phototherapy on serum magnesium levels in term newborns with hyperbilirubinemia admitted in tertiary care center

Background: Neonatal hyperbilirubinemia is a common condition that affects a significant proportion of term neonates. Phototherapy is the treatment of choice for this condition; however, it may influence various biochemical parameters, including serum magnesium levels. This study investigates the effect of phototherapy on serum magnesium levels in term neonates with hyperbilirubinemia. Methods: A descriptive observational study was conducted at the Department of Pediatrics, Al-Ameen Medical College, Vijayapura, Karnataka, over one year. Fifty term neonates (gestational age 37-42 weeks) diagnosed with hyperbilirubinemia and undergoing phototherapy were included. Serum magnesium and bilirubin levels were measured before and after 48 hours of phototherapy. Paired t-tests and Pearson’s correlation coefficient were used for statistical analysis. Results: The mean gestational age of neonates was 38.76±2.45 weeks. A significant reduction in serum magnesium levels was observed, with a decrease from 2.76±0.28 mg/dl pre-phototherapy to 1.87±0.12 mg/dl post-phototherapy (p=0.001). Serum magnesium levels showed a positive correlation with total bilirubin levels (r=0.76, p=0.001) and a negative correlation with the duration of phototherapy (r=-0.54, p=0.001). There were no significant differences in magnesium levels between the SGA, AGA and LGA groups. Conclusions: Phototherapy significantly reduces serum magnesium levels in term neonates with hyperbilirubinemia. This decrease in magnesium levels correlates with bilirubin levels and the duration of phototherapy. Clinicians should monitor magnesium levels, particularly in neonates undergoing prolonged phototherapy, to prevent complications associated with hypomagnesemia. Further studies are needed to assess the long-term effects and benefits of magnesium supplementation during phototherapy.