Background: High perinatal morbidity and mortality rates have been reported in association with absent or reverse end-diastolic flow velocities in the umbilical artery. Doppler of fetal venous blood flow might be a helpful instrument for predicting fetal outcome. However, clinical data addressing this issue are rare. Thus, the aim of this study was to evaluate arterial and ductus venosus blood flow velocities as a predictor of short-term outcome in fetuses with umbilical absent or reverse end-diastolic flow velocities.
Methods: Thirty-five high-risk single pregnancies complicated by umbilical absent or reverse end-diastolic flow velocities were monitored by serial measurement of the pulsatility index of the umbilical artery, middle cerebral artery, and ductus venosus waveforms over a period of 1-75 days.
Results: The mean observation period between first detection of an umbilical absent or reverse end-diastolic flow velocity and delivery was 8.9 days. A significant correlation was found between parameters of short-term perinatal outcome (art. pH, art. base excess, development of intraventricular hemorrhage, mortality) and end-diastolic flow velocity waveform or pulsatility index of the ductus venosus waveform, but not with arterial Doppler parameters. Gestational age proved to be the best predictor for duration of assisted ventilation and development of respiratory distress syndrome.
Conclusions: Our results indicate that in high-risk pregnancies with umbilical absent or reverse end-diastolic flow velocities, determination of blood flow velocities in the ductus venosus is a useful additional parameter for prediction of fetal outcome and for timing delivery.