Atypical ductus venosus blood flow pattern in fetuses with severe tricuspid valve regurgitation

We observed seven cases of atypical ductus venosus (DV) blood flow velocity waveform pattern with impairment of systolic forward flow resulting in a notch or a significant reduction in peak velocity during the S-wave in systole. All affected fetuses had severe tricuspid valve regurgitation associated with congestive heart failure and/or cardiac malformations. The decrease in venous systolic forward flow modulates the venous pulsatility indices towards more favorable values and should be considered when fetuses with tricuspid regurgitation are followed by Doppler assessment of the DV. Detection of these changes in the DV flow profile should prompt detailed color Doppler echocardiography with special emphasis on right atrioventricular valve regurgitation.