Critical comparison of indices and threshold values for assessing placenta performance using Doppler ultrasound.

To determine the most appropriate index and an optimal cutoff value for obstetric Doppler ultrasound, the umbilical and uterine arteries of 467 patients were examined during the third trimester using an Acuson 128 color Doppler system. Doppler ultrasound detection of chronic placental insufficiency with fetal growth retardation and acute placental insufficiency with subpartal asphyxia were selected as criteria. A birth weight below the 10th percentile (using Hohenauer's percentiles) was taken as the parameter for the former and a 5-minute Apgar score of < 8 for the latter criterion.

Development of quantitative Doppler indices for uteroplacental and fetal blood flow during the third trimester.

The aim of our study was to describe the development of uteroplacental and fetal blood flow during the third trimester. Doppler examination was carried out on 393 uncomplicated pregnancies with uncomplicated term delivery. Using a pulsed color Doppler, we calculated the maximum systolic, mean and maximum end-diastolic velocity after correcting the angle of insonation.