ABSTRACT
Umbilical venous waveforms by Doppler ultrasound are seen normally during fetal breathing
movements. Each waveform extends two to four fetal cardiac cycles. During Doppler
study of gross intrauterine growth retardation (IUGR) and twin to twin transfusion
cases, single or double peaked umbilical venous waveforms were detected with each
fetal cardiac cycle. Umbilical arterial Doppler study detected minimal, absent, or
reverse diastolic flow. In these fetuses, the ratio of right and left ventricular
diameters at the atrioventricular valve level was increased, and pulse-wave and color
Doppler study showed tricuspid regurgitation. This tricuspid regurgitation caused
reverse flow in the umbilical vein from the right atrium and inferior vena cava and
produced characteristic venous waveforms. These umbilical waveforms were associated
with gross IUGR or cardiac failure of the fetuses with perinatal morbidity and mortality.
Keywords
Umbilical vein - Doppler ultrasound - venous waveform
