Mid-trimester uterine artery Doppler screening as a predictor of adverse pregnancy outcome in high-risk women.
OBJECTIVE
To assess the value of uterine artery Doppler ultrasound screening, when performed in a clinical setting, to predict complications of impaired uteroplacental blood flow in high-risk women.


METHODS
A prospective audit.


METHODS
A total of 116 pregnancies in 114 women at high risk of pre-eclampsia and/or small-for-gestational-age (SGA) babies attending a maternal-fetal medicine clinic at National Women's Hospital, a tertiary referral hospital, Auckland, New Zealand.


METHODS
Uterine artery Doppler screening was performed as part of clinical practice between 22 and 24 weeks' gestation. A resistance index (RI) was calculated from each uterine artery and the presence or absence of a notch was determined. An RI of > 0.58 was defined as abnormal and an RI of > or = 0.7 was defined as very abnormal. The main outcome measures were: pre-eclampsia, SGA baby (birth weight < 10th centile), placental abruption, intrauterine death, 'all' and 'severe' outcomes.


RESULTS
Thirty-two (27.5%) women developed pre-eclampsia, 31 (26.7%) had SGA babies, 23 (20%) were delivered at < 34 weeks because of pregnancy complications, and there were three (2.6%) placental abruptions and three (2.6%) perinatal deaths. The sensitivity of any RI of > 0.58 for pre-eclampsia, SGA, 'all' outcomes and 'severe' outcome was 91%, 84%, 83% and 90%, respectively. The specificity of any RI of > 0.58 for these outcomes was 42%, 39%, 47% and 38%, respectively. The positive predictive value of any RI of > 0.58 for the same outcomes was 37%, 33%, 58% and 24%, respectively. Among women with both RI values of > or = 0.7, 58%, 67%, 85% and 58% developed pre-eclampsia, SGA, 'all' and 'severe' outcomes, respectively. In women with bilateral notches, 47%, 53%, 76% and 65% developed the respective outcomes. Women with both RI values of > or = 0.7 and women with bilateral notches had relative risks of 11.1 (95% CI 2.6-46.4) and 12.7 (95% CI 4.0-40.4) for developing severe outcome, respectively. Only 5% of women with both RI values of < 0.58 developed a severe outcome.


CONCLUSIONS
In high-risk women, uterine artery Doppler waveform analysis performed best in the prediction of severe adverse outcome and was better than clinical risk assessment in the prediction of pre-eclampsia and SGA babies. Further studies are necessary to determine how information from uterine artery Doppler studies should modify current practice in high-risk women.
Coleman
M A
MA
Department of Obstetrics and Gynaecology, University of Auckland, New Zealand.
McCowan
L M
LM
North
R A
RA
D000328:Adult; D001158:Arteries / Q000000981:diagnostic imaging; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D008485:Medical Audit; D021041:Placental Circulation; D011225:Pre-Eclampsia / Q000000981:diagnostic imaging* / Q000209:etiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D018566:Pregnancy, High-Risk; D011446:Prospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018608:Ultrasonography, Doppler / Q000379:methods*; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014599:Uterus / Q000098:blood supply* / Q000000981:diagnostic imaging*; D014655:Vascular Resistance