title: Uterine electromyography for identification of first-stage labor arrest in term nulliparous women with spontaneous onset of labor.
abstract: OBJECTIVE
  We sought to study whether uterine electromyography (EMG) can identify inefficient contractions leading to first-stage labor arrest followed by cesarean delivery in term nulliparous women with spontaneous onset of labor.
  
  
  METHODS
  EMG was recorded during spontaneous labor in 119 nulliparous women with singleton term pregnancies in cephalic position. Electrical activity of the myometrium during contractions was characterized by its power density spectrum (PDS).
  
  
  RESULTS
  Mean PDS peak frequency in women undergoing cesarean delivery for first-stage labor arrest was significantly higher (0.55 Hz), than in women delivering vaginally without (0.49 Hz) or with (0.51 Hz) augmentation of labor (P = .001 and P = .01, respectively). Augmentation of labor increased the mean PDS frequency when comparing contractions before and after start of augmentation. This increase was only significant in women eventually delivering vaginally.
  
  
  CONCLUSIONS
  Contraction characteristics measured by uterine EMG correlate with progression of labor and are influenced by labor augmentation.
authors.affiliation: Department of Obstetrics, University Medical Center, Utrecht, The Netherlands. b.vasak@umcutrecht.nl
authors.forename: Blanka
authors.initials: B
authors.lastname: Vasak
authors.forename: Elisabeth M
authors.initials: EM
authors.lastname: Graatsma
authors.forename: Elske
authors.initials: E
authors.lastname: Hekman-Drost
authors.forename: Marinus J
authors.initials: MJ
authors.lastname: Eijkemans
authors.forename: Jules H Schagen
authors.initials: JH
authors.lastname: van Leeuwen
authors.forename: Gerard H
authors.initials: GH
authors.lastname: Visser
authors.forename: Benoit C
authors.initials: BC
authors.lastname: Jacod
mesh_terms: D000328:Adult; D002585:Cesarean Section; D004576:Electromyography; D005260:Female; D006801:Humans; D007747:Labor Stage, First / Q000502:physiology*; D011247:Pregnancy; D011446:Prospective Studies; D014590:Uterine Contraction
keywords: cesarean delivery; electromyography; electromyography/EMG; labor arrest; parturition; uterine