To estimate the incidence of severe neonatal hyperbilirubinemia in Canada from 2011-2013 following the implementation of the Canadian Pediatric Society's published guidelines on the management of hyperbilirubinemia in 2007. Our previously reported incidence of hyperbilirubinemia in Canada was 1 in 2480.

Term infants ≤60 days of age, with a peak serum total bilirubin level >425 μmol/L or who had an exchange transfusion were followed prospectively through the Canadian Pediatric Surveillance Program from 2011-2013. Infants with rhesus isoimmunization or born <35 weeks gestation were excluded.

Ninety-one cases of severe neonatal hyperbilirubinemia were confirmed. Sixty-nine infants (76%) were readmitted to hospital, 47 (52%) of them within 6 days of age. The remaining 22 infants (24%) were identified with severe neonatal hyperbilirubinemia before they were discharged from the hospital. The mean reported peak bilirubin level was 484 μmol/L (range 181-788; SD ± 92). An etiology was identified in 57 (63%) cases, with ABO incompatibility (n = 35) and glucose-6-phosphate dehydrogenase deficiency (n = 11) being the most common. An infant was 3.5 times more likely to be diagnosed with severe neonatal hyperbilirubinemia from 2002-2004 compared with 2011-2013 (95% CI 2.72-4.47).

The minimum estimated incidence of severe neonatal hyperbilirubinemia in Canada is 1 in 8352 live births. Introduction of the Canadian Pediatric Society guidelines and improved physician awareness of severe neonatal hyperbilirubinemia in the last 10 years likely made positive contributions to this trend.