Flow velocity waveforms in the uterine artery in high risk pregnancies.

Blood flow velocity investigations by applying Doppler method have emerged as a useful tool in obstetrics and gynaecology. The final role of the method is still to be established. Thus far, the umbilical artery Doppler indices have been preferred to the utero-placental indices. We have analysed the Doppler indices from the main branch of uterine artery in 280 women with singleton pregnancy in the third trimester. While fetal blood flow velocities in the cerebral arteries or in the umbilical artery are still unchanged, the increase in the uterine artery resistance may serve as an early indicator of the increased risk to the fetus.