New Doppler Technique for Assessing Uteroplacental Blood Flow

Evaluation of the uterine and placental circulation

“…In the two groups of patients with impaired arcuate blood flow (LU) there was a high incidence of proteinuric hypertension which confirms our previous findings (6). It is interesting to note, however, that several patients who were studied serially moved from the LUNF to the LULF group but we have not observed interchange between the other groups.…”

“…Waveforms from fetal (1,2,3/4) and maternal (6) side of the placental circulation can readily be obtained using a duplex pulsed Doppler system (4) . Quantative measurement of blood flow may be subject to large errors (4) but useful information may be gained by study of the flow velocity waveforms (FVW) .…”

“…To remove the effect of the angle of insonation it is necessary to relate one part of the waveform to another. Maximum information is obtained by use of the frequency index profile (4,6) but this is complex and we are awaiting automatic computer analysis of this parameter.…”

Doppler ultrasound in the assessment of suspected intra-uterine growth restriction

“…Studies in women with hypertensive disease of pregnancy have reported that, in those with increased impedance (increased resistance index or the presence of an early diastolic notch), compared to hypertensive women with normal flow velocity waveforms, there is a higher incidence of pre-eclampsia, intrauterine growth restriction, emergency Cesarean delivery, placental abruption, shorter duration of pregnancy and poorer neonatal outcome (10) .…”

Evaluation of Fetal Growth and Fetal Well-Being

“…In these pregnancies the utero-placental circulation remains in a state of high resistance, which may cause generalized endothelial cell injury, compromising vascular integrity and an atherosis-like process with consequent small-vessel occlusion, local ischemia, and necrosis. 59 This condition can be noninvasively evaluated by Doppler ultrasound 60 : uterine artery Doppler measurements show that impedance to flow in the uterine arteries (ie, Resistance Index or S/D ratio) decreases with gestational age in normal pregnancies (Fig. 11A).…”