Currently, phototherapy is started in extremely low birth weight infants at low bilirubin levels without fear of harm. However, bilirubin as a natural antioxidant may reduce retinal damage caused by free radicals. There have been conflicting reports of the association between bilirubin levels and retinopathy of prematurity (ROP). Our aim was to study associations between bilirubin levels and adverse outcomes (neurodevelopmental deficit and blindness).

Methods: Retrospective study of 131 outborn infants of birth weight ≤800g and ≤27 weeks' gestation admitted between 1980-89 to a tertiary care NICU. Associations were analyzed between bilirubin levels, duration of phototherapy and potential confounding factors vs. neurodevelopmental outcome and blindness due to ROP. Binary bilirubin variables were defined as above vs. below 3 arbitrary levels (160, 180 and 200 umol/I).

Results: Of 131 survivors, 15 were blind and 21 had neurodevelopmental deficit. Blindness due to ROP was associated with gestational age (p=0.035), duration of phototherapy (p=0.021) and bilirubin concentrations below 160umol/I (p=0.031). There was a trend for bilirubin>200umol/1 to be associated with neurodevelopmental deficit. (p=0.074)

Conclusion: The aggressive use of phototherapy in extremely low birth weight infants may be harmful. If our results are confirmed by others, criteria for phototherapy need to be reconsidered.