COLOR DOPPLER IMAGING OF THE UTEROPLACENTAL CIRCULATION IN THE MIDTRIMESTER - FEATURES OF THE UTERINE ARTERY FLOW-VELOCITY WAVE-FORM THAT PREDICT ABNORMAL PREGNANCY OUTCOME

The accuracy of raised Resistance Index (RI) and early diastolic notch ing (EDN) of mid-trimester uterine artery flow velocity waveforms in p redicting abnormal pregnancy outcome was assessed in a prospective lon gitudinal study using colour Doppler imaging at 14, 18, and 24 weeks. In 106 healthy nulliparas with a singleton pregnancy studied; 70 had a normal pregnancy outcome, 34 had an abnormal pregnancy outcome, and 2 were lost to follow-up. EDN was more sensitive than raised RI at pred icting subsequent abnormal pregnancy outcome but raised RI was more sp ecific at 14 and 18 weeks. Sensitivities were highest for the pregnanc ies with the more severely abnormal outcomes. Uterine artery Doppler s tudies in the mid-trimester can predict abnormal pregnancy outcome. Th e presence of an early diastolic notch is an important feature when de fining an abnormal or high resistance uteroplacental circulation.