Economy circuit of fetal circulation illustrated on the basis of personal quantitative Doppler blood flow parameters

: Percentile curves of the mean blood flow velocity and the mean blood flow volume of the fetal aorta were calculated from a normal study group comprised of 290 pregnant women. Additionally ratios of the mean blood flow velocity or blood flow volume of the fetal common carotid artery and the fetal aorta were established. In a high risk group with a loss of end-diastolic blood flow velocities in the umbilical artery and/or fetal aorta and subsequent primary caesarean section due to fetal distress (pathological CTG) we investigated the course of the above mentioned parameters. The ratio of the mean velocity or the mean blood flow volumes showed and increased in all 10 cases of the high risk group from the first to the last measurement. In all cases the final level before the delivery was far above the 95th centile. The underlying pathophysiological occurrence of the conserving adaptation of the fetal circulation is expressed by the ratios. This is why we consider these parameters to be of great importance in the supervision of high risk pregnancies in the future.