title: Prediction of spontaneous vaginal delivery by transperineal ultrasound performed just after full cervical dilatation is determined.
abstract: OBJECTIVE
  To investigate whether transperineal ultrasound examination just after full cervical dilatation is determined can predict the mode of delivery.
  
  
  METHODS
  This was a prospective observational study of pregnant women. After full cervical dilatation was determined by vaginal examination during labor, transperineal ultrasound was immediately performed, and the head direction (HD), progression distance (PD), and angle of progression (AoP) were measured. The cases were divided into two groups: spontaneous vaginal delivery and operative delivery due to failure of progression. Differences between the groups were statistically analyzed using Student's t test and Fisher's exact test.
  
  
  RESULTS
  Of the 50 women, 42 had spontaneous vaginal deliveries and 8 had vacuum extractions. The spontaneous delivery group had significantly higher HD, PD, and AoP values than the vacuum extraction group. The areas under the receiver-operating characteristic curves for the prediction of spontaneous vaginal delivery were 0.850 for HD, 0.827 for PD, and 0.783 for AoP. The optimum cut-off points and positive predictive values were 83° and 92.9 % for HD, 56 mm and 94.9 % for PD, and 146° and 94.3 % for AoP, respectively.
  
  
  CONCLUSIONS
  Transperineal ultrasound examination just after full cervical dilatation was determined was useful in predicting spontaneous vaginal delivery.
authors.affiliation: Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
authors.forename: Saeko
authors.initials: S
authors.lastname: Kameyama
authors.affiliation: Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan. satoa@doc.med.akita-u.ac.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Sato
authors.affiliation: Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miura
authors.affiliation: Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Kumagai
authors.affiliation: Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Sato
authors.affiliation: Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
authors.forename: Dai
authors.initials: D
authors.lastname: Shimizu
authors.affiliation: Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Makino
authors.affiliation: Department of Obstetrics and Gynecology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita, 010-8543, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Terada
mesh_terms: D000328:Adult; D005260:Female; D006257:Head / Q000000981:diagnostic imaging / Q000196:embryology; D006801:Humans; D007747:Labor Stage, First; D011247:Pregnancy; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014620:Vacuum Extraction, Obstetrical
keywords: Angle of progression; Head direction; Labor; Progression distance; Transperineal ultrasound