title: First-trimester uterine artery Doppler and adverse pregnancy outcome: a meta-analysis involving 55,974 women.
abstract: OBJECTIVE
  To determine the accuracy with which uterine artery Doppler in the first trimester of pregnancy predicts pre-eclampsia and fetal growth restriction, particularly early-onset disease.
  
  
  METHODS
  We searched MEDLINE (1951-2012), EMBASE (1980-2012) and the Cochrane Library (2012) for relevant citations without language restrictions. Two reviewers independently selected studies that evaluated the accuracy of first-trimester uterine artery Doppler to predict adverse pregnancy outcome and performed data extraction to construct 2 × 2 tables. We synthesized sensitivity and specificity for various Doppler indices using a bivariate random-effects model.
  
  
  RESULTS
  From 1866 citations, we identified 18 studies (55,974 women). The sensitivity and specificity of abnormal uterine artery flow velocity waveform (FVW) in the prediction of early-onset pre-eclampsia were 47.8% (95% CI: 39.0-56.8) and 92.1% (95% CI: 88.6-94.6), and in the prediction of early-onset fetal growth restriction were 39.2% (95% CI: 26.3-53.8) and 93.1% (95% CI: 90.6-95.0), respectively. The sensitivities for predicting any pre-eclampsia and fetal growth restriction were 26.4% (95% CI: 22.5-30.8) and 15.4% (95% CI: 12.4-18.9), respectively, and the specificities were 93.4% (95% CI: 90.4-95.5%) and 93.3% (95% CI: 90.9-95.1), respectively. The number needed to treat (NNT) with aspirin to prevent one case of early-onset pre-eclampsia fell from 1000 to 173 and from 2500 to 421 for background risks varying between 1% and 0.4%, respectively.
  
  
  CONCLUSIONS
  First-trimester uterine artery Doppler is a useful tool for predicting early-onset pre-eclampsia, as well as other adverse pregnancy outcomes. Based on the NNT, abnormal uterine artery Doppler in low-risk women achieves a sufficiently high performance to justify aspirin prophylaxis in those who test positive.
authors: Women's Health Research Unit, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK; Women's Health Unit, Barts Health NHS Trust, London, UK.
authors: L
authors: L
authors: Velauthar
authors: M N
authors: MN
authors: Plana
authors: M
authors: M
authors: Kalidindi
authors: J
authors: J
authors: Zamora
authors: B
authors: B
authors: Thilaganathan
authors: S E
authors: SE
authors: Illanes
authors: K S
authors: KS
authors: Khan
authors: J
authors: J
authors: Aquilina
authors: S
authors: S
authors: Thangaratinam
mesh_terms: D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D021041:Placental Circulation; D011225:Pre-Eclampsia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011673:Pulsatile Flow; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D055988:Uterine Artery / Q000503:physiopathology*; D014599:Uterus / Q000098:blood supply / Q000000981:diagnostic imaging*
keywords: fetal growth restriction; first trimester; pre-eclampsia; uterine artery Doppler