The objective of this study was to investigate whether infants with total serum bilirubin > 450 umol/L in the neonatal period and no symptoms or no more than early acute bilirubin encephalopathy develop long term sequelae with impairment of motor development, hearing and executive function compared with a control group.

Children in both the exposed and the non-exposed group were examined by use of the MABC-2 and pure tone audiometry by the responsible examiner for the study, Pernille Vandborg, MD. The aim was to see whether the exposed group suffered any long term sequelae to the extreme neonatal hyperbilirubinemia, i.e. impaired motor development or hearing impairment, compared to a control group. The examinations took place at the local hospital.

Inclusion Criteria:

• Gestational age > 35 weeks
• Total serum bilirubin > 450 umol/L in the neonatal period
• Born in the period 01.01.2000 - 31.12.2005

Exclusion Criteria:

• Acute intermediate or advanced bilirubin encephalopathy

All children born in Denmark in the period 01.01.2000 - 31.12.2005 with a gestational age >= 35 weeks and a total serum bilirubin > 450 umol/L and a matched control group of children