Use or abuse of phototherapy for physiological jaundice of newborn infants.

To investigate the need for and effects of phototherapy in full-term otherwise healthy babies with physiological jaundice, 40 consecutive babies with serum bilirubin levels of 250 mumol/l or more were assigned at random to two treatment groups. Phototherapy was started in the early group (n = 20) when serum bilirubin was 250 mumol/l and in the late group (n = 20) when serum bilirubin reached 320 mumol/l; however, only 3 of the late group required treatment. Phototherapy prevented a further rise in bilirubin in almost all treated babies, but the difference in peak bilirubin level between early and late treatment groups was not significant. Early phototherapy produced a more rapid decline in bilirubin; levels fell to below 250 mumol/l in a median of 28 h with early treatment and 54 h with late treatment. In each group the ratio of boys to girls was 2/1 and boys remained jaundiced for significantly longer. Phototherapy therefore curtailed the rise and duration of hyperbilirubinaemia, but the effect was small. Jaundice subsided spontaneously in most of these mature infants, especially girls. Phototherapy can separate mother from baby, and it is physiologically stressful. Treatment may be safely withheld until serum bilirubin exceeds 320 mumol/l.