Trends in Extreme Neonatal Hyperbilirubinaemia: A Longitudinal Population-Based Case-Control Study

Area of Science:

• Neonatal Medicine
• Public Health Surveillance
• Epidemiology

Background:

• Extreme neonatal hyperbilirubinaemia (plasma bilirubin ≥ 450 μmol/L) poses significant health risks.
• Accurate incidence data is crucial for effective public health strategies.
• Previous Australian estimates relied on voluntary clinician reporting, potentially underestimating the true incidence.

Purpose of the Study:

• To determine the incidence, causes, and clinical associations of extreme neonatal hyperbilirubinaemia in South Australia.
• To compare incidence rates derived from population-based surveillance with previous estimates.
• To identify factors associated with extreme hyperbilirubinaemia and investigate temporal trends.

Main Methods:

• Population-based case-control study in South Australia (2010-2021).
• Identified neonates (≥ 36 weeks gestation) with extreme hyperbilirubinaemia via a state-wide pathology system.
• Utilized medical records for case details and SA Health data for controls.

Main Results:

• Identified 68 cases, with an incidence of 28.6/100,000 births over 12 years.
• Incidence was significantly higher than previous estimates based on clinician reporting (9.4/100,000).
• Associated factors included Asian ethnicity, ventouse delivery, and early discharge; a 2020 spike coincided with the SARS-CoV-2 pandemic onset.

Conclusions:

• The incidence of extreme neonatal hyperbilirubinaemia in South Australia remained stable but was higher than previously reported.
• Population-based laboratory surveillance is a more reliable method for monitoring incidence than voluntary clinician reporting.
• Pandemic-related changes in maternity care may have contributed to the 2020 incidence spike.