Follow-up of extreme neonatal hyperbilirubinaemia in 5- to 10-year-old children: a Danish population-based study

AIM: To investigate whether infants with neonatal hyperbilirubinaemia but without intermediate or advanced bilirubin encephalopathy develop long-term sequelae, with impairment of motor development, executive function, or hearing.

METHOD: This nested double-cohort study included 167 exposed children (107 males, 60 females) born in Denmark 2000 to 2005 at gestational age ≥35 weeks with a total serum bilirubin ≥450 μmol/L (26.3mg/dL) and 163 age-, sex-, and gestational age-matched unexposed children (103 males, 60 females). The children were examined at a mean age of 7.7 years (SD 1.7y) using the Movement Assessment Battery for Children-Second Edition (MABC-2), pure tone audiometry, and the Behavioural Regulation Inventory of Executive Function (BRIEF) questionnaire.

RESULTS: The follow-up rate was 70% of the eligible infants in the exposed group and 45% in the unexposed group. Mean difference was -0.2 (95% confidence interval [CI] -1.1 to 0.8) in adjusted standard score for MABC-2 and 0.3 (95% CI -2.9 to 3.5) in adjusted BRIEF executive composite standard score. No children had significant hearing impairment or a diagnosis of cerebral palsy, attention-deficit-hyperactive disorder, or autism spectrum disorder recorded in national registries.

INTERPRETATION: No evidence was found of an increased risk of deficits in motor development, executive function, or hearing in children with extreme hyperbilirubinaemia who did not have intermediate or advanced bilirubin encephalopathy.