Screening for Congenital Heart Disease by Prenatal Ultrasound. A Comparison of Two Decades in Western Australia

Background: Worldwide trends have demonstrated that there is a significant increase in detection rates of congenital heart disease (CHD) by prenatal screening. Aim: This study was aimed at assessing detection rates of CHD by prenatal ultrasound screening, comparing two decades (1990–1999 and 2000–2009). Method: A retrospective review of trends in the detection of CHD anomalies in Western Australia was undertaken between the periods of 1990 and 2009. Data were extracted from the Western Australian Register of Developmental Anomalies. This included four major anomalies – Atrioventricular Septal Defects (AVSD), Tetralogy of Fallot (TOF), Complete Transposition of Great arteries (TGA) and Single Ventricles and compared the pre and post natal detection rates including post mortem findings over two decades. Results: The number of patients diagnosed with CHD in Western Australia has remained unchanged over the previous two decades, accounting for approximately 1% of live births. Overall prenatal detection rates have increased from 14% (1990–1999) to 44% (2000–2009) era. Individually the rates of detection have also significantly increased; TOF 4.3–25.2%, AVSD 28–46.7%, single ventricle 43.5–85.7% and TGA 4–40%. Despite the increase there is still a significant proportion of CHD that remains undetected by prenatal ultrasound screening. Conclusion: This study has demonstrated an increase in the detection rates of CHD over two decades. Improvements are required at the screening level to further reduce the proportion of undetected cases of major cardiac anomalies.