Impact of phototherapy on multiple biochemical markers in Jaundiced neonates: A prospective comparative observational Study

Objective This study aimed to compare short-term changes in serum bilirubin, total calcium, hemoglobin, creatinine, and urinary calcium-to-creatinine ratio between jaundiced term/late-preterm neonates receiving phototherapy versus controls. Methods We performed a prospective comparative observational study at Gonabad University of Medical Sciences, Iran. Eighty term/late-preterm neonates with hyperbilirubinemia were grouped into to phototherapy (n = 40) and control (n = 40) groups. Serum hemoglobin, total calcium, creatinine, and urine calcium–creatinine ratio were assessed at baseline and 48 hours, adjusted via ANCOVA for baseline differences. Phototherapy employed LED/fluorescent devices (10–50 µW/cm²/nm) for approximately 20 hours until bilirubin levels normalized. Results The mean weight of the infants was 3105.7 ± 493.7 grams, and 57.5% of the babies were boys. Phototherapy reduced bilirubin by 38% (15.37 to 9.59 mg/dL; p < 0 .001). Contrary to the literature, calcium increased in the phototherapy group (8.78 to 9.38 mg/dL; p < 0.001) but decreased in controls. Hemoglobin remained stable with phototherapy but declined substantially in controls (− 3.92 g/dL; p < 0.001). Serum creatinine converged between groups, reflecting normal neonatal maturation. Conclusions Phototherapy appears to be an effective and safe phototherapy exposure for jaundiced neonates, leading to more favorable short‑term hematologic and biochemical profiles than standard care. These results suggest that phototherapy not only achieves substantial bilirubin reduction but also helps preserve hemoglobin and calcium status without adversely affecting renal function.