Clinical value of mid-pregnancy uterine artery Doppler velocimetry in the prediction of pregnancy complications

Purpose: Does a correlation exist between the development of pregnancy complications (hypertensive disease including HELLP-sydrome, IUGR < 5th centile and premature birth < 34 completed weeks) and uterine artery Doppler velocimetry from 18 + 0 to 23 + 6 weeks? Material and Methods: 780 pregnant women were examined during a detailed ultrasound scan for the exclusion of fetal malformations. Resistance-Index (RI) was calculated from both right and left uterine arteries. Data concerning course and outcome of pregnancy was complete in 645 cases. We excluded 39 cases because of maternal diseases and divided 606 cases into a "normal" group (no pregnancy complication and sufficient fetal outcome; n = 536) and a "pathologic" group (above mentioned pregnancy complications/insufficient fetal outcome; n = 66). We chose the 70th, 80th, 90th centile of the RI and the Notch as bilateral criterion and the 95th centile as unilateral criterion and calculated the true positive and negative and the false positive and negative values for all of them. Results: A sensitivity of 47% was proved to be the highest value using the 70th centile as cut-off. With the 90th centile as cut-off, a specificity of 98% and a positive predictive value of 70% were best. Using the 80th centile as cut-off, IUGR and premature birth were predicted correctly in 76% and 70%, respectively. Hypertensive disease was indicated in 43%. Specificity was 92% in all these cases. Conclusion: Uterine artery Doppler flow velocity waveform analysis is the only method to predict pregnancy complications in mid-pregnancy. The development of pregnancy complications can be excluded in 98%. Using the 90th centile as a bilateral cutoff, one third of all complications could be detected with a false positive rate of 30%. A positive predictive value of 70% exceeds significantly all comparable values known from the literature. In our opinion, uterine artery Doppler velocimetry should be used as a screening method in all pregnancies.