title: Maternal uterine artery Doppler flow velocimetry and the risk of stillbirth.
abstract: OBJECTIVE
  We sought to relate the risk of antepartum stillbirth to uterine artery Doppler flow velocimetry at 22-24 weeks.
  
  
  METHODS
  Data were available from 30,519 unselected women from seven units in the UK who had uterine artery Doppler performed between 22 and 24 weeks of gestation. The risk of stillbirth (n=109) was assessed using time to event and logistic regression analysis. Stillbirths were subdivided into placental (due to abruption, preeclampsia, or growth restriction) or unexplained.
  
  
  RESULTS
  The risk of placental stillbirth was increased among women with a mean pulsatility index in the top decile (adjusted hazard ratio [HR] 5.5, 95% confidence interval [CI] 2.8-10.6) and those with a bilateral notch (adjusted HR 3.9, 95% CI 2.0-7.8). The relationship between a mean pulsatility index in the top decile and the risk of unexplained stillbirth was weaker (adjusted HR 2.5, 95% CI 1.1-5.6) and there was no association with a bilateral notch. Placental stillbirths occurred at earlier gestations than unexplained stillbirths (median [interquartile range] 30 [26-36] compared with 38 [36-40], P<.001). Consequently, being in the top 5% of predicted risk of stillbirth on the basis of the combination of mean pulsatility index and notching was a good predictor (sensitivity, specificity, and positive likelihood ratio) of all cause stillbirth up to 32 weeks (58%, 95%, and 12.1, respectively) but a poor predictor of stillbirth at later gestations (7%, 95%, and 1.3, respectively).
  
  
  CONCLUSIONS
  Abnormal uterine artery Doppler was a better predictor of the risk of stillbirth due to placental causes than unexplained stillbirth. Consequently, abnormal uterine artery Doppler was a good predictor of stillbirth at extreme preterm gestations but a poor predictor of stillbirth at term.
  
  
  METHODS
  II.
authors.affiliation: Department of Obstetrics and Gynaecology, Cambridge University, Rosie Maternity Hospital, Cambridge, UK. gcss2@cam.ac.uk
authors.forename: Gordon C S
authors.initials: GC
authors.lastname: Smith
authors.forename: Christina K H
authors.initials: CK
authors.lastname: Yu
authors.forename: Aris T
authors.initials: AT
authors.lastname: Papageorghiou
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Cacho
authors.forename: Kypros H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D008403:Mass Screening; D010920:Placenta / Q000502:physiology; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012306:Risk; D050497:Stillbirth; D018608:Ultrasonography, Doppler; D014599:Uterus / Q000098:blood supply*