Prediction of the development of neonatal jaundice by increased umbilical cord blood bilirubin.

Umbilical cord serum bilirubin concentration as a predictor of subsequent jaundice was studied in 291 newborns. It was possible to define subgroups of infants with significantly higher or lower risks of developing jaundice. If cord bilirubin was below 20 mumol/l, 2.9% became jaundiced as opposed to 85% if cord bilirubin was above 40 mumol/l. Furthermore, 57% of jaundiced infants with cord bilirubin above 40 mumol/l required phototherapy, but only 9% if cord bilirubin was 40 mumol/l or lower (p less than 0.003). Knowledge of infants at risk of developing jaundice allows simple bilirubin reducing methods to be implemented before jaundice is present and could influence a decision regarding early discharge from hospital. Since the ability of plasma to bind bilirubin in cord blood from jaundiced and non-jaundiced infants showed no significant differences, the increased cord bilirubin among infants who later became jaundiced is presumably caused by increased fetal bilirubin production or decreased removal of bilirubin from the fetal circulation.