Study inclusion criteria
| Fetal anomaly scan abnormality | Antenatal risk factor |
|---|---|
| Suspected CHD on fetal anomaly scan | CHD in first-degree relative of fetus (requiring surgical or catheter intervention during first year of life) |
| Fetal dysrhythmia | Maternal IDDM |
| Hydrops fetalis | Exposure to teratogens associated with CHD (maternal or paternal) |
| Extra-cardiac fetal anomaly associated with CHD on fetal anomaly scan |
CHD, congenital heart disease; IDDM, insulin-dependent diabetes mellitus.