title: Ultrasonographic evaluation of myometrial thickness and prediction of a successful external cephalic version.
abstract: OBJECTIVE
  To test the hypothesis that myometrial thickness predicts the success of external cephalic version.
  
  
  METHODS
  Abdominal ultrasonographic scans were performed in 114 consecutive pregnant women with breech singletons before an external cephalic version maneuver. Myometrial thickness was measured by a standardized protocol at three sites: the lower segment, midanterior wall, and the fundal uterine wall. Independent variables analyzed in conjunction with myometrial thickness were: maternal age, parity, body mass index, abdominal wall thickness, estimated fetal weight, amniotic fluid index, placental thickness and location, fetal spine position, breech type, and delivery outcomes such as final mode of delivery and birth weight.
  
  
  RESULTS
  Successful version was associated with a thicker ultrasonographic fundal myometrium (unsuccessful: 6.7 [5.5-8.4] compared with successful: 7.4 [6.6-9.7] mm, P=.037). Multivariate regression analysis showed that increased fundal myometrial thickness, high amniotic fluid index, and nonfrank breech presentation were the strongest independent predictors of external cephalic version success (P<.001). A fundal myometrial thickness greater than 6.75 mm and an amniotic fluid index greater than 12 cm were each associated with successful external cephalic versions (fundal myometrial thickness: odds ratio [OR] 2.4, 95% confidence interval [CI] 1.1-5.2, P=.029; amniotic fluid index: OR 2.8, 95% CI 1.3-6.0, P=.008). Combining the two variables resulted in an absolute risk reduction for a failed version of 27.6% (95% CI 7.1-48.1) and a number needed to treat of four (95% CI 2.1-14.2).
  
  
  CONCLUSIONS
  Fundal myometrial thickness and amniotic fluid index contribute to success of external cephalic version and their evaluation can be easily incorporated in algorithms before the procedure.
  
  
  METHODS
  III.
authors.affiliation: Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University, New Haven, CT, USA. catalin.buhimschi@yale.edu.
authors.forename: Catalin S
authors.initials: CS
authors.lastname: Buhimschi
authors.forename: Irina A
authors.initials: IA
authors.lastname: Buhimschi
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Wehrum
authors.forename: Sherry
authors.initials: S
authors.lastname: Molaskey-Jones
authors.forename: Anna K
authors.initials: AK
authors.lastname: Sfakianaki
authors.forename: Christian M
authors.initials: CM
authors.lastname: Pettker
authors.forename: Stephen
authors.initials: S
authors.lastname: Thung
authors.forename: Katherine H
authors.initials: KH
authors.lastname: Campbell
authors.forename: Antonette T
authors.initials: AT
authors.lastname: Dulay
authors.forename: Edmund F
authors.initials: EF
authors.lastname: Funai
authors.forename: Mert O
authors.initials: MO
authors.lastname: Bahtiyar
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000000981:diagnostic imaging; D001946:Breech Presentation / Q000000981:diagnostic imaging / Q000628:therapy; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D009215:Myometrium / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D009929:Organ Size; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging; D011256:Pregnancy Outcome; D016896:Treatment Outcome; D014463:Ultrasonography; D014710:Version, Fetal