ABSTRACT
In a group of 154 mature normal neonates the authors recorded significantly higher mean alpha-fetoprotein values in children with hyperbilirubinaemia (higher than 205 mumol/l) than in other neonates. The differences were observed also in children of equal gestation age. Development of hyperbilirubinaemia is more probable and indication for phototherapy is significantly higher in neonates with alpha-fetoprotein levels in umbilical blood above 100 mg/l and these infants must be carefully observed. When the concentration is above 130 mg/l, the development of hyperbilirubinaemia may be assumed with certainty. Examination of alpha-fetoprotein in umbilical blood is an useful indicator of the functional maturity of the liver, but does not ensure reliable prediction of hyperbilirubinaemia in individual neonates. A concentration of alpha-fetoprotein above 100 mg/l is exceptional among neonates without hyperbilirubinaemia, while lower values do not rule out the development of hyperbilirubinaemia.