Characteristics of flow velocities in the umbilical arteries, assessed by Doppler ultrasound

Doppler assessment of the fetoplacental circulation and fetal growth; preliminary results

“…A previous study confirmed the intra-and inter-observer reproducibility of the method and demonstrated the feasibility of the signal processing technique used [1].…”

Doppler assessment of the fetoplacental circulation in normal and growth-retarded fetuses

“…Blood flow velocity signals from the umbilical arteries were recorded using a 4 MHz pulsed Doppler device (ALVAR). The Doppler recording procedure and extensive instrumental specifications, as well as the adequacy of the signal processing technique by zero-cross detection, have been previously described (Reuwer et al, 1984). A Gosling and King (1974).…”

“…1). A previous study (Reuwer et al, 1984) demonstrated the intra-and inter-observer reproducibility of PI values from umbilical arteries.…”

“…Recent reports on Doppler flow recordings from umbilical arteries suggest that this non-invasive technique may provide direct information as to the functional state of the placental villous circulation (McCallum et al, 1978;Stuart et al, 1980;Giles et al, 1983;Reuwer et al, 1984). The method is based on the principle that the pulsatility of arterial flow reflects downstream vascular resistance (Gosling and Ring, 1974;Skidmore et al, 1980).…”

A comparative study of three indices of umbilical blood flow in relation to prediction of growth retardation

“…-Pulsatility Index (PI) [4], is defined as the difference between peak-systolic and enddiastolic flow, divided by the mean flow ((A -B)/mean). Good negative correlations between fetal growth and the PI of the umbilical artery [2,11,12] and the fetal descending aorta [6] are reported, even weeks to months before IUGR was suspected clinically.…”