[The effect of body position on uterine blood flow in the 3d trimester of pregnancy].

Uterine vessels of 20 women with uncomplicated pregnancy between the 34th and 38th week of gestation were examined by means of Duplex sonography and a "simple" Doppler ultrasound device without sectional view and spectral analysis. Blood flow in several uterine vessels was recorded in various body positions: lying, sitting on a bench, standing, and - with some of the patients - in a position sitting on a so called "Variable Balance Chair". The relationship between the systolic and diastolic levels, as well as the shape of the Doppler curve, led to the Doppler parameters used. The Doppler parameters pointing to the best perfusion were found in the lying position, and sitting on the "Variable Balance Chair". Uterine perfusion seemed to be significantly decreased at the regular sitting, and in the standing position. Likewise, the shape of the Doppler curves indicated higher resistance in the blood vessels in the standing and the regular sitting position. The observations show that there are other factors that influence the momentary uterine perfusion besides uterine contractions. These results seem to be useful for the management of foetal growth retardation.