Objective: To evaluate the effect of phototherapy on total leukocyte count in neonates with hyperbilirubinemia. Design: Prospective observational study. Setting: Pediatric department of a tertiary care teaching hospital. Methods: 96 apparently healthy neonates who developed indirect hyperbilirubinaemia and required phototherapy irrespective of gestational age and birth weight included in the study. Neonates having septicemia, congenital porphyria or a family history of porphyria, conjugated hyperbilirubinaemia and receiving concomitantly drugs or agents that are photosensitizers were not included in the study. Leukocyte counts were performed at the time of admission (at the initiation of phototherapy), after 48 hours, and 96 hours of phototherapy. Results: After 48-96 hours of phototherapy there was a statistically significant drop in total leukocyte count observed in all babies irrespective of locality, antenatal or perinatal history, birth weight, gestational age, mode of delivery and postnatal age (P<0.05). Conclusions: Phototherapy (after 48-96 hours) causes decrease in leukocyte count in neonates with hyperbilirubinemia.
