Tetralogy of Fallot in the fetus: findings at targeted sonography

Objectives To evaluate the findings of tetralogy of Fallot in various fetal sonographic view. Methods We reviewed the fetal sonograms and medical records of 20 fetuses with Prenatal diagnosis of tetralogy of Fallot. We analyzed the indications for targeted sonography, the abnormalities seen in various sonographic views, the postnatal echocardiographic and angiographic findings and autopsy findings. Results The most common indication for targeted sonography was all abnormal (n=12) or inadequate (n=3) finding oil sonographic screening in which the abnormality was most frequently found on the three-vessel view (n=9). The key pathological features of tetralogy of Fallot were uniformly demonstrated in the ventricular outflow tract, three-vessel and short-axis views. The ductus arteriosus was small in 70% of cases and not identifiable in the remaining fetuses. In three of six fetuses with no identifiable ductus, the ductus was shown to be absent at autopsy The direction of ductal flow was variable. Conclusions The key features of tetralogy of Fallot were always demonstrable in the ventricular outflow tract, three-vessel and short-axis views. The most common reason for referral was the abnormal three-vessel view.