Congenital anomaly registers in Australia: A national challenge

<b>Background:</b> Robust population health surveillance is required to monitor trends in prevalence in congenital anomalies (CA) and to detect emerging threats to human development. All eight Australian states and territories are mandated to report CA data to national authorities. <b>Objectives:</b> (i) Compare Australian congenital anomaly registers (CARs) across jurisdictions; (ii) measure research utilisation of Australian CAR data. <b>Method:</b> We conducted a documentary analysis of publicly available online information on Australian CARs and performed a scoping review of peer-reviewed research published from 1980 to 2024 that utilised CAR data. <b>Results:</b> Five Australian states/territories possessed an established CAR; three practiced active surveillance, and three included mandatory reporting. Age of child inclusion criteria ranged from birth episode to 6 years. Most states/territories classified CAs according to the <i>International Classification of Diseases 10th Revision Australian Modification</i> (ICD-10-AM). There was inconsistency in scope, data sources, method of ascertainment, data linkage processes, data availability, reporting requirements and data quality. The scoping review identified 83 peer-reviewed publications using CAR data. The majority of publications originated from three states/territories and included key CAR staff as authors. Only one state/territory CAR consistently published research over the 44-year review period. <b>Conclusion:</b> There are major methodological inconsistencies among Australian CARs, undermining the interpretability and quality of nationally reported CA data. More standardisation and resourcing are required to maximise the research and policy value of Australian CARs. <b>Implications for health information management practice:</b> Urgent attention to data management practices, harmonisation across jurisdictions and resourcing are required to safeguard the sustainability and value of Australian CARs.