OBJECTIVE To evaluate alterations of arterial and ductus venosus blood flow velocities during deterioration and their interdependence. METHODS 37 high-risk pregnancies complicated by umbilical absent or reverse end-diastolic flow velocities (AREDV) were monitored by measurement of the pulsatility index of the umbilical artery, middle cerebral artery and ductus venosus waveforms. RESULTS The mean observation period was 16.5 days. There was a significant change in the pulsatility of waveforms in all vessels over the observation period. Compared with the ductus venosus, pulsatility of waveforms in the middle cerebral artery diverged from the normal range 2.2 weeks earlier. Increase in pulsatility in the umbilical artery was concomitant with venous but not with cerebral flow alterations. In addition, there was a correlation between the increase of venous but not arterial pulsatility and perinatal acidemia. Variability of pulsatility index values of the umbilical artery and the ductus venosus but not of the middle cerebral artery increased towards delivery. CONCLUSIONS Ductus venosus Doppler allows detection of further deterioration in centralized fetuses with umbilical AREDV. However, striking short-term variability has to be taken into account when considering this parameter.