Multicenter screening for adverse pregnancy outcomes by uterine artery Doppler in the second and third trimester of pregnancy.

Aims: Increased uterine artery pulsatility index (PI) is associated with adverse pregnancy outcomes. The aim of the study was to determine the role of uterine artery PI at 18-24 and 30-34 weeks, gestation in predicting adverse pregnancy outcomes.
Material and Methods: Color Doppler assessment of the uterine arteries was carried out in 435 consecutive women attending an antenatal clinic at 18-24 weeks and in 134 women at 30-34 weeks. The 95th percentiles of the mean uterine PI and the presence or the absence of bilateral notches was recorded. Using the reference range, performance characteristics in the prediction of pregnancy outcomes were calculated. Association of mean PI at 30-34 weeks with pregnancy outcomes also was studied. The adverse pregnancy outcomes were defined as any or the combination of pre-eclampsia, fetal growth restriction, intrauterine fetal death, preterm delivery and placental abruption.
Results: The women with adverse pregnancy outcomes had significant higher mean PI (1.27 +/- 0.55 vs. 0.99+/-0.32; p=0.003) and higher prevalence of bilateral notch (20% vs. 4.6%, p=0.001) than those with normal outcomes. The mean (+/-SD) PI in women with severe adverse outcome was 1.66+/-0.66 vs. 1.0+/-0.32 in women with normal pregnancy outcome (p=0.002). For a screen positive rate of 10.6% (mean PI>95th percentile for gestational age and/or bilateral notches), the sensitivity for predicting an adverse outcome was 33.3%. The sensitivity increased to 60% for predicting a severe adverse outcome. Increased resistance in the third trimester was also associated with an adverse pregnancy outcome.
Conclusion: Increased uterine artery PI in second and third trimester of pregnancy is associated with an increased risk of adverse pregnancy outcomes.