Abnormal umbilical artery doppler waveform during pregnancy Reversed end-diastolic umbilical artery flow 2022-04-10T13:46:23Z An anomaly that is visualized by umbilical artery Doppler velocimetry. Flow in the umbilical artery should be in the forward direction in normal circumstances. This anomaly is characterized by an reversal of flow in the umbilical artery at the end of diastole (i.e., backwards flow).