title: Competing risk model in screening for preeclampsia by mean arterial pressure and uterine artery pulsatility index at 30-33 weeks' gestation.
abstract: OBJECTIVE
  To assess risk for preeclampsia (PE) based on maternal characteristics, mean arterial pressure (MAP) and uterine artery pulsatility index (Ut-PI) at 30-33 weeks' gestation.
  
  
  METHODS
  Screening study in singleton pregnancies including 2,140 that subsequently developed PE and 83,615 that were unaffected by PE, gestational hypertension or delivery of small-for-gestational-age neonates (normal group). We developed a survival time model for the time of delivery for PE by combination of maternal characteristics and history with MAP and Ut-PI multiple of the median (MoM) values (biophysical test). Data on third-trimester MAP and Ut-PI were available in 350 cases of PE and 13,878 of the normal group. The detection rate of PE requiring delivery within 4, 6 and 8 weeks of the visit was estimated.
  
  
  RESULTS
  In pregnancies with PE the log10 MoM values of MAP and Ut-PI were inversely related to gestational age at delivery. Biophysical testing detected 90, 65 and 53% of PE with delivery within 4, 6 and 8 weeks of the visit, at a fixed false-positive rate of 5%.
  
  
  CONCLUSIONS
  Testing by maternal characteristics, Ut-PI and MAP at 30-33 weeks could identify 90% of pregnancies developing PE and requiring delivery within the subsequent 4 weeks.
authors: Harris Birthright Research Centre of Fetal Medicine, King's College Hospital, London, UK.
authors: Ahmet
authors: A
authors: Tayyar
authors: Santiago
authors: S
authors: Garcia-Tizon Larroca
authors: Leona C
authors: LC
authors: Poon
authors: David
authors: D
authors: Wright
authors: Kypros H
authors: KH
authors: Nicolaides
mesh_terms: D000328:Adult; D062186:Arterial Pressure / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D008954:Models, Biological; D011225:Pre-Eclampsia / Q000175:diagnosis* / Q000503:physiopathology; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000502:physiology*; D011296:Prenatal Diagnosis / Q000379:methods; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology*; D055988:Uterine Artery / Q000502:physiology*