Second and third trimester Doppler P75Uterine artery Doppler velocimetry in low risk nulliparous women

Abstract

BackgroundThe aim of this study was to assess how placental position and gestational age can influence the value of a diastolic notch of the uterine arteries as a screening test for pre‐eclampsia, in a low risk population of healthy nulliparous women.MethodsColor Doppler ultrasound was used to examine both uterine arteries in 654 healthy nulliparas at four‐weekly intervals between 20 and 32 weeks (wks). The only criterion for an abnormal result was the presence of an early diastolic notch. In each subject the placental position was also recorded.ResultsTwenty‐one out of 654 women developed pre‐eclampsia (3.2%). The sensitivity of the test becomes lower as gestational age advances and ranged from 81% at 20 wks, to 71.4% at 32 wks. In contrast the specificity and positive predictive value increase significantly. Eleven out of 12 women who delivered before 34 wks had abnormal waveforms at 24 wks. In women with a full lateral placenta the predictive value of the test was extremely low.ConclusionPre‐eclampsia can be more accurately predicted if along with the presence of a notch, both gestational age and placental position are taken into account.