The impact of phototherapy in the management of neonatal hyperbilirubinemia: comparison of historical cohorts.

To quantitatively assess the impact of phototherapy (PT) in the prevention of kernicterus we calculated the rate of exchange transfusion (ET) in two large historical cohorts of Greek neonates (birthweight > or = 2.5 kg), one before (period I: 1957-61) and one after (period II: 1980-92) the introduction of PT. Overall, the introduction of PT was associated with a reduction of the rate of ET from 0.43% in period I to 0.05% in period II. The reduction was observed in all etiological categories but was more marked in the ABO-incompatible group. With an estimated rate of kernicterus without treatment of 0.085% (excluding rhesus hemolytic disease of the newborn and prematurity) we estimated that 4.2 and 0.36 infants were treated by ET for each spared kernicterus in periods I and II, respectively. Finally, in period II 185 infants were treated with PT or PT and ET for each spared kernicterus.