title: Is it possible to detect malposition of the vertex at an early stage in labour? A case-control study.
abstract: OBJECTIVE
  The aim of this study was to investigate if there are clinical signs which allow detection of malposition of the vertex on admission to the delivery unit, or when crossing the action line on the partogram.
  
  
  METHODS
  Case-control study from 2007 to 2010 conducted on the delivery unit of Nordland Hospital, Bodø. Labours with malposition of the vertex (n = 171) were compared with a group with normal vertex presentation (n = 165). The positive predictive value was estimated for each sign using Bayes' rule.
  
  
  METHODS
  Magnitude of positive predictive value for each clinical sign.
  
  
  RESULTS
  The positive predictive values for malposition were 9% if the foetus were in a right position, 11% if the labour was induced, 5% if the foetus was above the ischial spines, 4% if the reason for admission was contractions and 6% if cervix was <3 cm.
  
  
  CONCLUSIONS
  The ability of clinical assessment to predict malposition, either on admission or when crossing the action line on the partogram, was poor. Diagnosing malposition of the vertex requires other methods with a higher predictive value.
authors.affiliation: Department of Maternal and Child Health, The Delivery Unit, Nordland Hospital, Bodø, Norway. Electronic address: marit.mathisen@live.com.
authors.forename: Marit
authors.initials: M
authors.lastname: Mathisen
authors.affiliation: Department of Maternal and Child Health, The Delivery Unit, Nordland Hospital, Bodø, Norway.
authors.forename: Rudi Valde
authors.initials: RV
authors.lastname: Olsen
authors.affiliation: Department of Maternal and Child Health, The Delivery Unit, Nordland Hospital, Bodø, Norway; The University of Tromsø, Norway.
authors.forename: Stine
authors.initials: S
authors.lastname: Andreasen
authors.affiliation: Department of Emergency Medicine, Nordland Hospital, Bodø, Norway; The University of Nordland, Norway; The University of Tromsø, Norway.
authors.forename: Erik Waage
authors.initials: EW
authors.lastname: Nielsen
mesh_terms: D001499:Bayes Theorem; D016022:Case-Control Studies; D002584:Cervix Uteri; D002585:Cesarean Section; D036861:Delivery, Obstetric; D042241:Early Diagnosis; D005260:Female; D005333:Fetus; D006801:Humans; D007751:Labor, Induced / Q000009:adverse effects; D007743:Labor, Obstetric; D007744:Obstetric Labor Complications / Q000175:diagnosis* / Q000209:etiology; D011247:Pregnancy; D012189:Retrospective Studies
keywords: Labour; Malposition of the vertex; Positive predictive value; Quantitative study