Obstetric outcome in Danish children with a validated diagnosis of kernicterus

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.