Impact of antenatal screening on the presentation of infants with congenital heart disease to a cardiology unit

Aim: Antenatal diagnosis of congenital heart disease (CHD) facilitates prenatal treatment and optimal perinatal care. This has been demonstrated to improve perinatal mortality and morbidity in neonates with CHD. Thus, antenatal diagnosis of CHD is most likely to benefit patients who require surgery in early infancy. We aimed to examine the frequency of antenatal diagnosis in neonates presenting to The Royal Children's Hospital severe CHD. Methods: Main outcome measures were antenatal diagnosis and whether the individual lesion would have been expected to be detected on a four-chamber view or four-chamber and outflow tract view during a routine obstetric anomaly ultrasound. Poisson regression was used to estimate the average trend over the study period. Results: A total of 610 patients met the inclusion criteria, of whom 164 had an antenatal diagnosis (26.8%). If routine ultrasound screening was ideal, we would have expected 63.9% of cases to be detected on four-chamber view and 83.6% on four-chamber and outflow tract view. Trend analysis demonstrated an annual rate of improvement of 9% in actual versus expected antenatal diagnosis of CHD. Malformation-specific analysis showed that antenatal detection was the highest for double inlet/outlet ventricle (51.3%, 95% confidence interval 34.8-67.6%) and the lowest for simple transposition of the great arteries (15.6%, 95% confidence interval 9.0-24.5). Conclusion: Despite mass screening for congenital malformations in Victoria with routine antenatal ultrasounds, a large proportion of neonates with severe congenital heart disease still present without an antenatal diagnosis.