Introduction Studies at tertiary referral centres have shown the antenatal detection of major cardiac anomalies (those defined as requiring surgery or intervention in the first year of life) is as high as 70–80%. However, recent data produced from the Central Cardiac Audit Centre statistics puts the detection rate at only 22–50% with the overall average being 30% across strategic health authorities in the UK. With such a wide variety of detection rates across different centres, it is unclear what the benchmark for secondary care detection actually is. The authors therefore examined the antenatal detection rate of major cardiac anomalies in our secondary care unit. Women are offered first trimester Down's syndrome screening with Nuchal translucency. An Anomaly scan at 19–20 weeks is performed by sonographers who have had training in four chamber and outflow tract views.

Method A retrospective 7-year review of patients whose babies were diagnosed with a major cardiac abnormality and whether they were detected ante or postnatally.

Results 17 726 patients were scanned ante-natally in our unit from 2002 to 2008. There were a total of 74 cases of major cardiac abnormalities of which 43 were detected at or prior to their 20-week anomaly scan (detection rate 58%).

Conclusion This review establishes that the detection rate of major cardiac anomalies in a secondary referral unit is 58%.