Almost all newborn infants develop a total serum or plasma bilirubin (TB) value greater than 1 mg/dL (17.1 micromol/L), which is the upper limit of normal for adults. As TB increases, it causes neonatal jaundice, the yellowish discoloration of the skin and/or conjunctiva caused by bilirubin deposition in half of all newborn infants .
Hyperbilirubinemia in infants ≥35 weeks gestational age (GA) is defined as TB >95th percentile on the hour-specific Bhutani nomogram . Hyperbilirubinemia with a TB >25 to 32 mg/dL (428 to 547 micromol/L) is associated with an increased risk for bilirubin-induced neurologic dysfunction (BIND), which occurs when bilirubin crosses the blood-brain barrier and binds to brain tissue. The term "acute bilirubin encephalopathy" (ABE) is used to describe the acute manifestations of BIND. The term "kernicterus" is used to describe the chronic and permanent sequelae of BIND. Appropriate intervention is important to consider in every infant with severe hyperbilirubinemia. However, even if these infants are adequately treated, long-term neurologic sequelae (kernicterus) can sometimes develop.
The treatment of neonatal unconjugated hyperbilirubinemia is reviewed here. The clinical manifestations, evaluation, pathogenesis, and etiology of this disorder are discussed separately. (See "Clinical manifestations of unconjugated hyperbilirubinemia in term and late preterm infants" and "Evaluation of unconjugated hyperbilirubinemia in term and late preterm infants" and "Pathogenesis and etiology of unconjugated hyperbilirubinemia in the newborn".)
Two advances in medical care had a significant impact on the need for treatment and the way in which hyperbilirubinemia is managed. The administration of Rh (D) immunoglobulin to Rh-negative mothers in the late 1960s dramatically decreased the incidence of neonatal Rh isoimmune hemolytic disease. At about the same time, the introduction of phototherapy in the United States significantly reduced the need for exchange transfusions and the risk of severe hyperbilirubinemia. Thus, the risk of kernicterus significantly decreased from its peak incidence in the 1950s to the 1970s. Nevertheless, isolated cases of kernicterus, a preventable condition, continue to be reported. (See "Clinical manifestations of unconjugated hyperbilirubinemia in term and late preterm infants", section on 'Overview'.)
Limited data based upon case reports suggest that kernicterus occurs in term or late preterm infants with hyperbilirubinemia, defined as total serum or plasma bilirubin (TB) >95th percentile on the hour-specific Bhutani nomogram . In order to prevent future cases of kernicterus, the management of unconjugated hyperbilirubinemia focuses on two key elements: