[Pulsed Doppler flow measurements using a vaginal ultrasound probe--integration into fetomaternal hemodynamics]

A recently developed "Panorama" sector scanner emitting in frontal direction (KretzTechnik, Zipf, Austria), combined with pulsed Doppler signal processing, makes it possible to visualize the main branch of the uterine artery already during its passage through the parametrium, and to adjust the Doppler beam under visual control. This makes it possible for the first time to receive flow signals that are free from superimpositions and are reliable, from both vessels supplying the pregnant uterus. It was the aim of our study to describe the haemodynamic changes at the uterine arteries in the course of pregnancy and to collect first experiences on the blood flow of the entire uterus. 42 women with an uneventful course of pregnancy were examined between the 8th and the 40th week of pregnancy. Angle-independent parameters such as the A/B ratio and pulsatility index dropped significantly during the course of pregnancy. The A/B ratio dropped from 5.4 during the first trimenon to 2.2 during the third trimenon, and the pulsatility from 2.6 to 1.3. This new method makes it possible to receive at more reliable and in respect of the total blood flow of the uterus more representative values for insertion into the second part of the haemodynamic equation for the pregnant uterus.