The clinical implications of absent or reversed end-diastolic frequencies in umbilical artery flow velocity waveforms

We describe the clinical details of 37 pregnancies with loss or reversal of end-diastolic frequencies in the umbilical artery, as detected by Doppler ultrasound. This finding is an ominous sign of serious fetal compromise in the majority of cases, with a high incidence of growth retardation, oligohydramnios, preterm delivery and maternal hypertension. However, current knowledge does not indicate when these pregnancies should be delivered. The possible pathophysiology and available literature are discussed.