Objective: To validate the use of the kernicterus diagnosis in a clinical register in Denmark and to describe occurrence and obstetric outcome in children with a validated kernicterus diagnosis.
Design: Population-based cohort study.
Setting: Denmark.
Population: All children born from 1 January 1994 to 31 December 2003.
Methods: We established a national population-based cohort of children with a diagnosis of kernicterus based on data obtained from a mandatory national register and from a clinically established cohort. Information on obstetric outcome and child development was obtained from the registers and from the medical records.
Main outcome measures: Validation of the kernicterus diagnosis and description of obstetric and long-term outcomes in children with kernicterus.
Results: We found 15 children with a diagnosis of kernicterus in the Danish National Hospital Register and eight children with a diagnosis of kernicterus in a clinically established cohort. A total of nine children had a validated diagnosis of kernicterus which leads to a cumulative incidence of kernicterus in Denmark of 1.3/100.000 newborns. Most of the nine children experienced suboptimal growth but otherwise normal pregnancy and delivery outcomes. All except one child developed severe neurological impairment in childhood.
Conclusion: Kernicterus is still an existing disease in Denmark. The children with kernicterus experienced overall normal pregnancy and delivery outcomes but long-term outcomes were affected. Validation of the kernicterus diagnosis in the hospital register was necessary.