Figure 1. Flow diagram illustrating the multiple sources used to formulate the cases of major congenital anomalies in the ALSPAC cohort.

All 30 CA cases within HeartSuite had a CHD diagnosis. Note that the potential capture population for each source may differ and cannot be definitively quantified. Abbreviations: ALSPAC, Avon Longitudinal Study of Parents and Children; CA, congenital anomaly; CHD, congenital heart disease; NHS, National Health Service.