Utero-placental blood flow velocity waveforms as predictors of pregnancy-induced hypertension.

Sixty high-risk pregnancies were studied in order to define the validity of the analysis of utero-placental blood flow velocity waveforms in early screening for developing hypertensive diseases. Recordings were obtained at 18-20 weeks gestation, in normotensive patients, using a pulsed duplex Doppler system at the level of uterine vessels. The patients (n = 22) who developed hypertension showed a higher resistance index value (p less than 0.001) than normotensive patients (n = 38). The validity of uteroplacental waveform analysis was as follows: specificity = 84.2%; sensitivity = 63.6%; positive predictive value = 70%; negative predictive value = 80%; accuracy = 76.6%. The high specificity attained suggests that this test can adequately identify, among a high-risk population, patients destined to remain normotensive during pregnancy.