title: Radiographic measures of the mid pelvis to predict cesarean delivery.
abstract: OBJECTIVE
  The purpose of this study was to determine whether x-ray measures of the mid pelvis can be used to predict cesarean delivery.
  
  
  METHODS
  Women were enrolled prospectively; x-ray pelvimetry was performed after delivery; the readers were blinded to the outcome. Groups were determined by mid pelvis measures (transverse diameter, anteroposterior diameter, and circumference ≤ 10th percentile. The primary outcome was cesarean delivery. Univariable, stratified, and multivariable analyses were performed to estimate the effect of mid pelvis measures on cesarean delivery. Receiver operator characteristics curves were created to estimate the predictive value of mid pelvis measures of cesarean delivery.
  
  
  RESULTS
  Four hundred twenty-six women were included. Subjects with anteroposterior diameter or circumference ≤ 10th percentile were at greater risk of cesarean delivery (risk ratio for anteroposterior diameter, 4.8; 95% confidence interval, 3.9-5.8; risk ratio for circumference ≤ 10th percentile, 3.8; 95% confidence interval, 3.1-4.8). Transverse diameter ≤ 10th percentile was not associated with an increased risk of cesarean delivery. The area under the receiver operator characteristics curves for anteroposterior diameter, circumference ≤ 10th percentile, and transverse diameter were 0.88, 0.85, and 0.69, respectively (P < .01).
  
  
  CONCLUSIONS
  Simple radiographic measures of the mid pelvis on x-ray can provide a useful adjunct to clinical information in the determination of who should attempt a vaginal delivery.
authors: Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA.
authors: Lorie M
authors: LM
authors: Harper
authors: Anthony O
authors: AO
authors: Odibo
authors: David M
authors: DM
authors: Stamilio
authors: George A
authors: GA
authors: Macones
mesh_terms: D000293:Adolescent; D000328:Adult; D002585:Cesarean Section; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016017:Odds Ratio; D010387:Pelvimetry; D010388:Pelvis / Q000000981:diagnostic imaging*; D049590:Postpartum Period; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D011859:Radiography; D018570:Risk Assessment; D055815:Young Adult