[The importance of measuring both umbilical arteries for accuracy in Doppler ultrasound studies].

In a quarter of our Doppler investigations differences between the S/D-ratios of the arteries of one umbilical cord were more than 20%. In these cases one Doppler value was decided to be normal and the other to be pathological. In cases with two pathological values most caesarean sections because of fetal distress had to be performed and most SGA babies were born. There were relatively more caesarean sections and SGA babies in cases with one normal value and one pathological value than in cases with two normal Doppler values. Sensitivity and specificity of perinatal risks like intrauterine growth retardation or caesarean section because of fetal distress were different depending on which Doppler value was used to calculate these statistical parameters. Taking always the better values compared to the worse ones we found as greatest difference 20.0% for sensitivities and 24.1% for specificities. Taking the means of the better and the worse Doppler values we found as greatest difference 5.6% for sensitivities and 8.7% for specificities compared to the cases with two identical Doppler results. To decide whether the fetus is jeopardized and to describe the nutritional function of the placenta correctly by means of Doppler ultrasound of the umbilical artery we conclude that in some cases the investigation of both arteries is important to avoid false positive or false negative results.