Evaluation of the effect of phototherapy on neonates' serum magnesium level: systematic review

Neonatal jaundice, amongst the most prevalent neonatal ailments with a prevalence of 60%, is defined as elevated serum levels of bilirubin. Phototherapy is the cornerstone for treating neonatal jaundice. The effect of phototherapy on magnesium serum levels is not well studied. Therefore, through this review article, we aim at assessing changes of serum magnesium levels during phototherapy.  

In this systematic review article, domestic databases of University Jihad, Civilica, and university journals in addition to PubMed database are searched without time limit. Studies which assessed the effect of phototherapy on serum magnesium level were reviewed and the results were reported. All articles were separately reviewed by two authors.

Two hundred and twenty-two articles were extracted from the mentioned databases. Applying the inclusion and exclusion criteria, 14 articles were selected for thorough assessment. As shown in most of these studies, phototherapy had a significant effect on decreasing serum magnesium levels in neonates. Only one study did not show any significant effect. Most studies have not evaluated demographic and clinical variables in decreasing serum magnesium levels.

There is a significant relationship between phototherapy and serum magnesium levels. Considering the role of NMDA receptor and its stimulatory effect in brain damage due to hypoxia and hyperbilirubinemia and the importance of magnesium in its inhibition, the body increases the extracellular magnesium levels during neonatal jaundice to prevent brain damage. It is concluded that after phototherapy, and therefore resolution of hyperbilirubinemia, serum magnesium level is reduced.