title: Uterine artery Doppler screening for pre-eclampsia: comparison of the lower, mean and higher first-trimester pulsatility indices.
abstract: OBJECTIVE
  A previous study suggested that the lower uterine artery pulsatility index (PI) is a better predictor of pre-eclampsia than is either the mean or higher indices. The aim of this study was to assess the relative value of these three indices for the prediction of pre-eclampsia in the first trimester of pregnancy.
  
  
  METHODS
  This was a prospective study of 6221 singleton pregnancies. Uterine artery PI was obtained at the time of the 11-14-week nuchal translucency scan and receiver-operating characteristics curves for the lower, mean and higher PI value of the two uterine arteries in the prediction of pre-eclampsia were calculated.
  
  
  RESULTS
  There were 178 cases of pre-eclampsia. The associations between uterine artery PI and pre-eclampsia were stronger for early (requiring delivery < 34 weeks' gestation) and preterm (requiring delivery < 37 weeks) pre-eclampsia compared to pre-eclampsia at any gestation. There was no significant difference in the strength of the association between lower, mean and higher PI for pre-eclampsia at any gestation.
  
  
  CONCLUSIONS
  First-trimester uterine artery PI is strongly associated with the development of early and preterm pre-eclampsia. Lower, mean and higher uterine artery PIs are comparable in screening for pre-eclampsia. Any differences that exist between the lower, mean and higher uterine artery indices are unlikely to have a significant impact on screening sensitivities.
authors.affiliation: Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology, St George's Hospital Medical School, London, UK.
authors.forename: R
authors.initials: R
authors.lastname: Napolitano
authors.forename: R
authors.initials: R
authors.lastname: Rajakulasingam
authors.forename: A
authors.initials: A
authors.lastname: Memmo
authors.forename: A
authors.initials: A
authors.lastname: Bhide
authors.forename: B
authors.initials: B
authors.lastname: Thilaganathan
mesh_terms: D000328:Adult; D005260:Female; D005865:Gestational Age; D006801:Humans; D011225:Pre-Eclampsia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000502:physiology; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology*; D012372:ROC Curve; D018615:Ultrasonography, Doppler, Color / Q000379:methods; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055988:Uterine Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology