Incidence of chronic bilirubin encephalopathy in Canada, 2007-2008

Despite the implementation of screening guidelines to identify infants at risk for hyperbilirubinemia, chronic bilirubin encephalopathy (CBE) continues to be reported worldwide in otherwise healthy infants. The incidence of CBE in Canada is unknown. The objectives of this study were to establish the incidence of CBE in Canada and identify epidemiological and medical risk factors associated with its occurrence.

Data on infants were collected prospectively through the Canadian Pediatric Surveillance Program. Infants born between January 1, 2007 and December 31, 2008 were included if they either had symptoms of CBE and a history of hyperbilirubinemia, or if they presented in the newborn period with severe hyperbilirubinemia and an abnormal MRI finding as per the reporting physician.

During the study period, 20 cases were identified; follow-up data were available for 14 of these. The causes for the hyperbilirubinemia included glucose-6-phosphate dehydrogenase deficiency (n = 5), sepsis (n = 2), ABO incompatibility and other red blood cell antibodies (n = 7). Fifteen infants had abnormal brain MRI findings during the neonatal period. At follow-up, 5 infants developed classic choreoathetoid cerebral palsy, 6 had spectrum of neurologic dysfunction and developmental delay (as described by the reporting physician), and 3 were healthy.

CBE continues to occur in Canada at an incidence that appears to be higher than previously reported.