UMBILICAL VENOUS DOPPLER WAVE-FORM WITHOUT FETAL BREATHING - ITS SIGNIFICANCE

Umbilical venous waveforms by Doppler ultrasound are seen normally dur ing fetal breathing movements. Each waveform extends two to four fetal cardiac cycles. During Doppler study of gross intrauterine growth ret ardation (IUGR) and twin to twin transfusion cases, single or double p eaked 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 increase d, and pulse-wave and color Doppler study showed tricuspid regurgitati on. This tricuspid regurgitation caused reverse flow in the umbilical vein from the right atrium and inferior vena cava and produced charact eristic venous waveforms. These umbilical waveforms were associated wi th gross IUGR or cardiac failure of the fetuses with perinatal morbidi ty and mortality.