Abstract
Objective. To assess the role of first trimester uterine artery Doppler in pregnancies previously complicated by pre-eclampsia. Design and setting. Case-control study in two tertiary referral hospitals. Sample. A total of 56 singleton pregnancies in women with a previous pregnancy complicated by pre-eclampsia (Group 1). For each case, two parous controls (Group 2) and two nulliparous controls (Group 3) with normal pregnancy outcome were matched. Methods. Doppler examination of the uterine arteries at 11–14 weeks’ gestation. Main outcome measures. Mean uterine artery resistance index (UtARI) and notching. Pregnancy outcome. Results. UtARI did not vary significantly between the three groups (0.73, 0.70 and 0.71, respectively). Women in Group 1 had a significantly higher prevalence of uterine artery notching than those in Group 2 (73 vs 57%, p=0.04). In Group 1, the UtARI and prevalence of notching was not significantly increased when pregnancies were subsequently complicated by pre-eclampsia (p=0.60 and 0.61, respectively). However, in 12 pregnancies requiring delivery before 37 weeks due to pre-eclampsia, fetal growth restriction, abruption or intrauterine fetal death, the UtARI was significantly higher than in the 44 pregnancies with normal outcome (p=0.04). A combination of UtARI and notching showed sensitivities up to 75% and negative predictive values up to 88% for adverse outcome before 37 weeks. Conclusions. In pregnancies following a previous gestation complicated by pre-eclampsia, first trimester uterine artery Doppler findings are similar to those observed in nulliparous women. In these high-risk women, a combination of UtARI and notching can predict the risk of adverse outcome before 37 weeks.