The role of phototherapy in neonatal nonphysiologic jaundice as a risk factor for nephrolithiasis

one of the known complications of phototherapy in the treatment of jaundice in newborns is the reduction of serum calcium and the cause of this phenomenon is still not well defined. The aim of this study was to investigate the effect of phototherapy on increasing calcium urinary excretion and to answer the question whether phototherapy can be associated with increased urinary excretion of calcium as a risk factor for nephrolithiasis?

In this cross-sectional study 77 infants less than 2 weeks of age with normal weight who were hospitalized for non-physiologic jaundice were enrolled in a sampling study. These infants lack systemic underlying disease and were not treated with Antibiotics - No serum therapy and blood transfusion. Urine specimens were taken at the time of admission and 48 hours after phototherapy of newborns and ca, cr in urine was measured. Then, the ratio Ca/Cr was calculated. Finally, the obtained data was entered into SPSS 19 software and analyzed.

Average random urine Ca/Cr ratio before phototherapy was 0.38± 0.03 and the average random urine of ca/cr after phototherapy was 0.674 ± 0.26. The difference between the mean of Ca/Cr ratio of neonates with jaundice before and after phototherapy was significant (P <0.001) in 49.4% of neonates hypercalciuria was seen (Ca/Cr > 0.8).

According to the findings of this study, which indicates an increase in urinary excretion of calcium, phototherapy in newborns can be considered as a risk factor for the incidence of hypercalciurea and nephrolithiasis.