Severe hyperbilirubinemia in the UK

Increased serum bilirubin (hyperbilirubinemia) and consequent jaundice are common during the neonatal period. Around 50 % of newborns develop some degree of jaundice, during the first week of life, but for the vast majority this is mild (serum bilirubin peaking no higher than 150-200 µmol/L) and spontaneously resolves with no long-term consequences over the next week or so. 

However, if serum bilirubin rises above around 350-400 µmol/L there is increasing risk of kernicterus (deposition of toxic unconjugated bilirubin in brain cells) and resulting acute bilirubin encephalopathy, a serious condition associated with seizures and risk of permanent disability (e.g. cerebral palsy, hearing loss) or even death. 

Despite the availability of effective treatments (phototherapy and exchange transfusion) that reduce serum bilirubin to safe levels, US and Danish studies suggest a resurgence of severe hyperbilirubinemia and resulting encephalopathy. Concern about these reports prompted the first ever prospective study to determine the incidence and outcome of severe hyperbilirubinemia in the UK population. 

During a 2-year (2003-2005) study period, all UK pediatric consultants were asked in monthly mailings to report the clinical details of all new cases of severe hyperbilirubinemia (defined as unconjugated serum bilirubin >510 µmol/L in the first month of life). A total of 108 cases were identified, giving a UK incidence of 7.1/100,000 live births. 

Twenty cases presented in hospital and the rest were readmissions with severe jaundice following hospital discharge. Mean peak serum bilirubin was 580 µmol/L (range 510-802). Fourteen of the 108 infants showed signs of acute bilirubin encephalopathy, three of whom subsequently died. Six infants were left permanently disabled and three were in good health at 12 months. 

In an accompanying editorial the author welcomes the study and makes a plea for national guidelines for assessment and management of neonatal hyperbilirubinemia, emphasizing that kernicterus is a preventable condition. Each case is a "failure of clinical observation and awareness to identify jaundice in a timely manner".