[Pathophysiologic and clinical aspects of measuring blood flow in utero-placental vessels, the umbilical artery, the fetal aorta and the fetal common carotid artery]

Abstract

It was the aim of this study to conduct simultaneous qualitative analysis of blood flow spectra of uteroplacental and foetal vessels in normal pregnancy, in growth retardation and in EPH gestosis using the pulsed Doppler method. In 237 women who had delivered we performed 291 measurements in uteroplacental vessels, 318 in the umbilical artery, 339 in the foetal aorta and 130 in the foetal common carotid artery. The blood flow spectra were evaluated with the help of the resistance and pulsation index ratio (RI/PI) as a measure of the resistance of the subsequent vascular system. We observed in uteroplacental vessels in EPH gestosis and retardation a significant elevation of the index values in the wall of the uterus outside or inside the placental margin. In foetal vessels we noted a highly significant increase of RI and PI in the umbilical artery and the foetal aorta--simultaneously, however, a drop in the index values in the foetal common carotid artery. These changes point on the one hand to the increased resistance in the capillary net of the placenta and a possible vascular constriction in the region of the lower abdominal organs and extremities, whereas on the other hand they point towards a compensatory lowering of the vascular resistance in the cerebral circulation--possibly as an expression of the risk of hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)