[An update on unconjugated neonatal hyperbilirubinaemia in Denmark].

Approximately 60% of term newborn infants are jaundiced during the first week of life, which is caused by unconjugated bilirubin. Bilirubin encephalopathy is seen with severe hyperbilirubinaemia, when unbound bilirubin crosses the blood-brain barrier. The chronic form is called kernicterus spectrum disorder. To avoid this devastating condition, the treatment of choice for neonatal hyperbilirubinaemia is phototherapy, which is most efficient with LED light of 478-nm wavelength. In this review, we argue, that a systematic approach to hyperbilirubinaemic infants as well as surveillance of extreme neonatal hyperbilirubinaemia is highly important.

Extreme neonatal hyperbilirubinemia and kernicterus spectrum disorder in Denmark during the years 2000-2015.

OBJECTIVE: To determine the incidence and etiology of extreme neonatal hyperbilirubinemia, defined as total serum bilirubin (TSB) ≥450 µmol/L, and kernicterus spectrum disorder (KSD) in Denmark between 2000 and 2015. STUDY DESIGN: We identified all infants born between 01.01.2000 and 31.12.2015 with TSB ≥450 µmol/L, ratio of conjugated to TSB <0.30, gestational age ≥35 weeks, and postnatal age ≤4 weeks, using Danish hospitals' laboratory databases. RESULT: We included 408 infants. The incidence of extreme neonatal hyperbilirubinemia among infants with gestational age ≥35 weeks was 42/100,000 during the study period with a seemingly decreasing incidence between 2005 and 2015. Twelve of the 408 infants developed KSD, (incidence 1.2/100,000) Blood type ABO isohemolytic disease was the most common explanatory etiology. CONCLUSIONS: Our study stresses the importance of a systematic approach to neonatal jaundice and ongoing surveillance of extreme neonatal hyperbilirubinemia and KSD.

Extreme neonatal hyperbilirubinemia, acute bilirubin encephalopathy, and kernicterus spectrum disorder in children with galactosemia.

BACKGROUND: Galactosemia has not been recognized as a cause of extreme neonatal hyperbilirubinemia, although growing evidence supports this association. METHODS: In a retrospective cohort study, we identified children with galactosemia due to GALT deficiency using the Danish Metabolic Laboratory Database. Among these, we identified children with extreme neonatal hyperbilirubinemia or symptoms of ABE. Extreme neonatal hyperbilirubinemia was defined as maximum total serum bilirubin (TSBmax)) level ≥450 µmol/L and a ratio of conjugated serum bilirubin/TSB <0.30. RESULTS: We identified 21 children with galactosemia (incidence:1:48,000). Seven children developed extreme neonatal hyperbilirubinemia (median [range] TSBmax level: 491 [456-756] µmol/L), accounting for 1.7% of all extreme neonatal hyperbilirubinemia cases. During the first 10 days of life, hyperbilirubinemia was predominantly of unconjugated type. Four children developed symptoms of intermediate/advanced ABE. One additional child had symptoms of intermediate/advanced ABE without having extreme neonatal hyperbilirubinemia. On follow-up, one child had KSD. CONCLUSIONS: Galactosemia is a potential cause of extreme neonatal hyperbilirubinemia, ABE, and KSD. It is crucial that putative galactosemic children are treated aggressively with phototherapy to prevent ABE and KSD. Thus it is important that galactosemia is part of the work up for unconjugated hyperbilirubinemia.