title: Protocol for measurement of mean arterial pressure at 11-13 weeks' gestation.
abstract: OBJECTIVE
  To identify the best protocol for measurement of mean arterial pressure (MAP) in early pregnancy for the prediction of preeclampsia (PE).
  
  
  METHODS
  This was a prospective study in singleton pregnancies attending for a routine hospital visit at 11-13 weeks' gestation when a minimum of four recordings of MAP were taken from each arm. The performance of screening for PE by different combinations of MAP was compared to the protocol of the National Heart Foundation of Australia (NHFA).
  
  
  RESULTS
  The MAP was measured in 587 (2.4%) cases that developed PE and in 22,900 that were unaffected by hypertensive disorders in pregnancy. The area under the receiver operating characteristic curve (AUROC) for prediction of PE by MAP as recommended by the NHFA protocol was 0.773 (95% CI 0.768-0.778). This AUROC was not significantly different from the AUROC obtained by the average MAP of the first three measurements from one arm (0.765, 95% CI 0.760-0.771) or the average of the first (0.766, 95% CI 0.760-0.771), the first two (0.771, 95% CI 0.766-0.777), or the first three measurements from the two arms (0.773, 95% CI 0.768-0.778).
  
  
  CONCLUSIONS
  Performance of screening for PE by taking the average of a minimum of two measurements from both arms is comparable to the NHFA protocol.
authors.affiliation: Harris Birthright Research Centre of Fetal Medicine, King's College Hospital, London, UK.
authors.forename: L C Y
authors.initials: LC
authors.lastname: Poon
authors.forename: N A
authors.initials: NA
authors.lastname: Zymeri
authors.forename: A
authors.initials: A
authors.lastname: Zamprakou
authors.forename: A
authors.initials: A
authors.lastname: Syngelaki
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
mesh_terms: D001795:Blood Pressure Determination / Q000379:methods; D005260:Female; D006801:Humans; D011225:Pre-Eclampsia / Q000175:diagnosis*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D018570:Risk Assessment