DOPPLER ASSESSMENT OF THE UTERINE AND UTEROPLACENTAL CIRCULATION IN THE 2ND-TRIMESTER IN PREGNANCIES AT HIGH-RISK FOR PREECLAMPSIA AND OR INTRAUTERINE GROWTH-RETARDATION - COMPARISON AND CORRELATION BETWEEN DIFFERENT DOPPLER PARAMETERS/

During a 20-month period we studied 175 pregnant women at high risk fo r hypertensive disorders of pregnancy or intrauterine growth retardati on, and 172 patients at low risk, in a prospectively designed cross-se ctional trial. Using duplex pulsed wave Doppler ultrasound, we recorde d blood velocity waveforms from both main uterine arteries, the uterop lacental arteries in the region of placental implantation and the umbi lical artery at 21-24 weeks of gestation. Persistent notches in the ma in stem uterine arteries and elevated resistance indices of > 0.68 in the uterine arteries and > 0.38 in the uteroplacental arteries were de fined as abnormal waveforms. The incidence of proteinuric pregnancy-in duced hypertension (PPIH) and intrauterine growth retardation (IUGR) w ere recorded as main outcome measures. Doppler proved to be more effic ient at predicting a complicated pregnancy in those patients who were at high risk: a positive medical history alone was associated with a t hree-fold greater risk of developing PPIH and/or IUGR. In the high-ris k group a single pathological Doppler sign accounted for an additional three- to four-fold increased risk, and the combination of all three pathological signs, a seven-fold additional risk for later disease. In this group PPIH and/or IUGR was found in 58.3%, compared to 8.3% if D oppler results were normal. The criterion for the definition of pathol ogical Doppler results, whether persistent notching, the resistance in dex (RI) of the main stem uterine artery, of the RI in the arteries of the uteroplacental bed, was of minor importance, as all Doppler param eters were strongly correlated. However, the combination of all parame ters was superior to a single parameter, and a bilateral notch was sup erior to a unilateral notch in terms of minimizing false-positive resu lts. However, Doppler was less powerful in the population at low risk. Here PPIH and/or IUGR was seen in 6.1-6.4% in the group with abnormal Doppler findings compared to 5.2% in pregnancies with normal findings . None of the patients showed bilateral notching. In conclusion, patho logical Doppler velocimetry of the uterine and uteroplacental circulat ion was a powerful predictor of PPIH and/or IUGR in high-risk pregnanc ies, identifying a group in which 58.3% would suffer from disease late r in pregnancy. A combination of several Doppler parameters was superi or to a single parameter, although the parameters were strongly correl ated with each other.