Screen the fetal heart with five transverse planes — situs, four-chamber, left and right outflow tracts, three-vessel and three-vessel-trachea — because most major congenital heart disease is missed on the four-chamber view alone.
Orient first
- ISUOG recommends outflow tracts in addition to the four-chamber view (verify the current guideline).
- Normal four-chamber: heart occupies a third of the chest, axis ~45° to the left, equal-sized ventricles, offset AV valves.
- Transposition, tetralogy and arch anomalies have a normal four-chamber view.
Acquire the study
- Transabdominal ultrasound with the fetal chest magnified, sweep from the abdomen to the upper mediastinum; colour Doppler across valves and the arch.
The manoeuvre
- Situs: stomach and heart on the left; aorta left of the spine and IVC to the right in the upper abdominal plane.
- Four-chamber view: size, axis in degrees, septum, offset of the tricuspid valve.
- Left ventricular outflow: aorta arises from the LV, continuous with the septum.
- Right ventricular outflow: pulmonary artery crosses the aorta and bifurcates.
- Three-vessel-trachea view: size and order (PA, aorta, SVC), arches forming a V to the left of the trachea; colour Doppler for forward flow.
What confirms it
- An abnormality in one of the five planes — refer for fetal echocardiography.
What licenses you to exclude it
- Five normal planes make major congenital heart disease much less likely but do not exclude it.
The classic misread
- Accepting a four-chamber view as a complete cardiac screen.