Fetal Ultrasound Assessment of Ductus Venosus

Definition and Clinical Significance

The American College of Obstetricians and Gynecologists defines an increased ductus venosus pulsatility index (PI) as a value above the 95th percentile for gestational age, with abnormality primarily determined by qualitative waveform analysis showing decreased, absent, or reversed flow during atrial contraction 1
Decreased, absent, or reversed flow in the A-wave during atrial contraction represents the key abnormal finding linked to adverse outcomes, indicating myocardial impairment and increased ventricular end-diastolic pressure from elevated right ventricular afterload 1, 2, 3
Abnormal waveforms are directly linked to neonatal acidemia and perinatal mortality in growth-restricted fetuses 1, 2, 3

Normal ductus venosus shows continuous forward flow throughout the cardiac cycle with a biphasic waveform pattern 1, 2, 3
The presence of absent or reversed A-wave flow is more clinically actionable than a mildly elevated PI percentile, as it indicates imminent cardiovascular decompensation requiring delivery consideration 1, 2

Mistaking the inferior vena cava for the ductus venosus is the most frequent technical error 1, 2
Proper identification requires color Doppler showing aliasing at the site where the ductus venosus branches from the umbilical vein 1, 2
Measurements should be obtained in transverse or sagittal views of the fetal abdomen at the diaphragm level 1, 2

Abnormal A-wave flow has direct correlation with neonatal acidemia and mortality in intrauterine growth restriction 1, 2, 3
The American College of Radiology recommends that this represents late-stage cardiovascular compromise requiring urgent clinical decision-making 4, 5