Effects of Phototherapy on the Serum Magnesium Level in Neonates with Indirect Hyperbilirubinemia: A Prospective Cohort Study

Abstract

Objectives. Neonatal jaundice or hyperbilirubinemia is one of the common findings in neonatal medicine. Severe disease can cause neurological damage and even Kernicterus. Magnesium ion is the most important N-methyl-D-aspartate receptor antagonist. The most commonly used treatment for jaundice is phototherapy, but the effect of phototherapy on serum magnesium is less investigated. In this study, we aim to investigate the effects of phototherapy on total serum magnesium levels in icteric neonates. Methods. This prospective cohort study was carried out on 160 neonates with jaundice referring to the Besat Hospital of Hamadan. Based on the bilirubin level, newborns were divided into three subgroups of mild, moderate, and severe disease which were subjected to single, double, and intensive phototherapy, respectively. Serum bilirubin and magnesium levels were measured before and after phototherapy and compared using parametric tests. Results. Subjects have a mean intrauterine age of 38.8 weeks and a jaundice onset age of 3.8 days. In all groups, serum magnesium levels were within the normal range before phototherapy. After phototherapy, on the other hand, the most reduction of total serum magnesium was in the double phototherapy group, which was − 0.13 ± 0.42 mg / dl ( P = 0.018 ). The change in serum magnesium level was not significant in the single phototherapy ( − 0.02 ± 0.25 ) and intensive phototherapy ( − 13.55 ± 2.73 ) groups ( P > 0.05 ). Conclusion. In the present study, serum magnesium did not increase significantly before the treatment in three groups. After treatment, a significant reduction was seen in the double phototherapy group.

Neonatal Phototherapy Adverse Effects in Infants: A Scoping Review

“…The magnesium levels were significantly decreased with use of double phototherapy (p=0.018) but not with single phototherapy. 31 In a three cohort (infants at term, preterm and low birthweight) prospective observational study with a total sample of 100 by Chinnappa, et al hyponatremia was significant in study infants that underwent phototherapy, especially in preterm and low birthweight infants. Potassium changes in the study by were non-significant.…”

“…Of the three studies that explored adverse effects of neonatal phototherapy on electrolytes in the infant, there were significant decreases in neonatal magnesium levels 30,31 and in sodium levels. 30,32 Two of the studies did not find evidence of significant changes in potassium levels.…”

“…30,32 In the study by Eghbalian, et al where phototherapy dose dependent changes were found for serum total magnesium levels, one aspect to consider in determination of phototherapy versus hyperbilirubinemia as the causation, is that infants with higher bilirubin levels generally are prescribed double phototherapy, while infants without risk factors and with lower levels needing phototherapy may be prescribed single treatment. 31 Although the study results may provide information on an adverse effect of decreased magnesium levels with higher levels of neonatal phototherapy, it is important to consider the physiologic aspects of magnesium in the newborn. According to Sapkota, N-methyl-D-aspartate (NMDA) is a glutamate receptor that has an important role in synaptic physiological functions and memory.…”