Doppler Measurement of Uterine Blood Flow in the First Trimester of Normal and Complicated Pregnancies

Abstract

The technique of doppler ultrasound has revolutionized our understanding of the changes in uteroplacental blood flow impedance that occur in human pregnancy. Several reports in the last few years have examined the use of doppler ultrasound to detect blood velocity changes in maternal (Campbell et al., 1983), umbilical (Trudinger et al., 1986), and fetal vessels (Griffin et al., 1984). Both pulsed (Erskine and Ritchie, 1985) and continuous wave doppler (Trudinger et al., 1985) have been used to study the flow velocity waveforms in normal and abnormal pregnancies. These studies have concentrated on the latter half of pregnancy, in an attempt to assess the potential clinical value of this non invasive test for the screening and subsequent management of high risk pregnancies.