Predictive value of uterine artery velocimetry at midgestation in low- and high-risk populations: a new perspective.

OBJECTIVE: The aim of this study was to assess the value of uterine artery Doppler velocimetry performed at 18-20 and 22-24 weeks of gestation in predicting preeclampsia and adverse pregnancy outcome in low- and high-risk patients. METHODS: 865 pregnant women were evaluated: 335 and 530 pregnant women represented the high- and low-risk groups, respectively. Doppler ultrasound examination of the uterine arteries was performed at 18-20 weeks of gestation in 385 patients and at 22-24 weeks of gestation in 659 patients. Pregnancy outcome was evaluated in terms of: onset of preeclampsia; birth weight <2,500 g; birth weight <1,750 g; delivery before 36 weeks, and delivery before 32 weeks. RESULTS: At 18-20 weeks of gestation the sensitivity for the prediction of preeclampsia was 100 and 94% in low- and high-risk groups, respectively. Excellent negative predictive values towards birth weight <1,750 g (97% in low-risk and 93% in high-risk groups) and delivery prior to 32 weeks of gestation (99% in low-risk and 95% in high-risk groups) were obtained. At 22-24 weeks of gestation the sensitivity for the prediction of preeclampsia was 100 and 97% in low- and high-risk groups, respectively. Negative predictive values towards birth weight <1,750 g were 97% in low-risk and 94% in high-risk groups, whereas towards delivery prior to 32 weeks of gestation they were 98% in low-risk and 94% in high-risk groups. CONCLUSION: Doppler evaluation of the uterine artery at 18-20 and 22-24 weeks of gestation represents a useful predictive test in high-risk pregnancy and can also be used in prenatal surveillance of a low-risk population.