Uterine artery Doppler at 30-33 weeks' gestation in the prediction of preeclampsia.

OBJECTIVE: To investigate the potential value of measuring uterine artery pulsatility index (PI) at 30-33 weeks' gestation in the prediction of preeclampsia (PE) developing at or after 34 weeks.

METHODS: Screening study in singleton pregnancies at 30-33 weeks' gestation including 4,294 cases that were unaffected by PE, gestational hypertension (GH) or delivery of small for gestational age neonates (normal group), 145 that subsequently developed PE, with 37 cases requiring delivery at 34-37 weeks (intermediate-PE) and 108 delivering at or after 38 weeks (late-PE) and 161 that developed GH. The a priori risks for intermediate- and late-PE from maternal demographic characteristics and medical history were derived by logistic regression analysis. The a posteriori risks were calculated by combining the a priori risks with the likelihood ratios for uterine artery PI, which were calculated from fitted bivariate gaussian distributions.

RESULTS: In screening for PE by a combination of maternal characteristics and uterine artery PI, the estimated detection rates of intermediate- and late-PE, at a false-positive rate of 10%, were 70.3 and 54.6%, respectively.

CONCLUSION: Combined testing by maternal characteristics and uterine artery PI at 30-33 weeks could effectively identify women at high risk for subsequent development of PE.