Prevention of kernicterus: new guidelines and the critical role of family physicians.

In the 1940s and the 1950s, severe neonatal hyperbilirubinemia and kernicterus were most often encountered with hemolytic disease of newborn (HDN), which occurs most often as a result of the incompatibilities of the Rh and ABO blood groups. With the advent of prenatal testing, maternal Rh°(D) immunoglobulin, phototherapy, and exchange transfusion, the incidence of severe hyperbilirubinemia drastically decreased to the point that most physicians practising today have never encountered a bilirubin-induced neurologic disorder. Children affected with complications of hyperbilirubinemia can present with choreoathetoid cerebral palsy, dystonia, sensorineural hearing loss, paralysis of upward gaze, and dental enamel dysplasia. Unfortunately, severe hyperbilirubinemia continues to be the most common cause of neonatal readmission to hospital in North America, and kernicterus continues to occur in infants without risk factors or evidence of HDN. In Canada, a recent 2-year Canadian Paediatric Surveillance Program study of severe hyperbilirubinemia reported 258 cases of term infants, 60 days of age or younger, with either exchange transfusion or an unconjugated bilirubin level of 425 μmol/L or greater. Most of these infants (72%) were readmitted to hospital at a median age of 5 days. More important, 81% of infants were exclusively breastfed, and 11% of confirmed cases had a documented 10% to 15% weight loss. Of those with available data, only 36% had a cause identified; the most common cause was ABO blood group incompatibility and glucose-6–phosphate dehydrogenase (G6PD) deficiency.1 Regardless of the rarity of kernicterus even with bilirubin levels of 425 μmol/L, readmission creates potentially unnecessary distress and disruption for these families and can be prevented.