[Transvaginal Doppler ultrasound in early pregnancy--normal values and comparison with a risk sample with threatened abortion].

In the study introduced here, norm values for embryo-feto-placental circulation are illustrated. The values were gained by examining 75 singleton pregnancies of uncomplicated course and ending with non-problematic birth of an eutrophic child. In addition to qualitative parameters such as A/B-ratio and Pulsatility Index, the maximum systolic frequency shift was measured by transvaginal Doppler sonography between the fifth and 24th week of gestation (post menstruation), to obtain another quantitative parameter. The increasing circulation can be impressively visualized by viewing the corresponding norm value curves. This is valid for both the embryo-fetal as well as maternal side of the placenta. Over the same time period, 53 high-risk pregnancies with symptoms of premature labor were followed to enable comparison with the circulatory changes in normal pregnancy. It was not possible to differentiate normal and abnormal pregnancy regarding premature labor by examining the utero-feto-placental unit with transvaginal Doppler sonography. In direct comparison, the Doppler values showed no significant differences. The norm curves introduced in this study should be considered as a basis to evaluate the utero-feto-placental circulatory system using Doppler sonography and be of use to differentiate abnormal changes of perfusion during the course of pregnancy, soby making it possible to recognize a pregnancy at risk early on.