DOPPLER VELOCITY WAVE-FORM ANALYSIS OF THE FETAL VENOUS PRECARDIAC BLOOD-FLOW IN NORMAL AND COMPLICATED PREGNANCIES

Precardiac venous blood flow, umbilical artery and aortal blood flow of 120 unselected patients has been investigated by means of Doppler ultrasound. Measuring a hepatic vene directly before entering the inferior vena cava we found a characteristic blood flow pattern with a moderate foreward flow during systole and a small foreward flow during early diastole and a very small reverse flow because of atrial contraction during late diastole. We found changes in this flow pattern with reduction of the mean velocity in cases of high risk pregnancies with intrauterine growth retardation. Comparing normally developed fetuses with growth-retarded fetuses and vaginal delivery or caesarean sections without fetal distress with caesarean sections because of fetal distress we found significant differences with lower mean velocities in the precardiac venes of the latters. Comparing the precardiac venous flow velocities with the umbilical artery flow velocities and the fetal descending aortal flow velocities we found similar results of statistical values predicting growth retardation and caesarean section because of fetal distress. We concluded that venous Doppler flow velocity analysis is also able to predict perinatal risks like intrauterine growth retardation or caesarean section because of fetal distress as good as flow velocimetry of the umbilical artery or the fetal aorta; if it is impossible to demonstrate the fetal descending aorta or the vena cava inferior sonographically correctly the investigation of the hepatic vene may give you more reliable Doppler values for your clinical management.