title: Predicting Cesarean Delivery After Induction of Labor Among Nulliparous Women at Term.
abstract: OBJECTIVE
  To identify independent risk factors for cesarean delivery after induction of labor and to develop a nomogram for predicting cesarean delivery among nulliparous women undergoing induction of labor at term.
  
  
  METHODS
  This is a retrospective cohort study including nulliparous women with singleton, term (37 0/7 weeks of gestation or greater), cephalic pregnancies undergoing induction of labor from July 1, 2006, through May 31, 2012, at a tertiary care academic center. Inductions were identified using International Classification of Diseases, 9th Revision codes. Demographic, delivery, and outcome data were abstracted manually from the medical record. Women with a contraindication to vaginal delivery (malpresentation, abnormal placentation, prior myomectomy) were excluded. Independent risk factors for cesarean delivery were identified using logistic regression.
  
  
  RESULTS
  During the study period, there were 785 nulliparous inductions that met study criteria; 231 (29.4%) underwent cesarean delivery. Independent risk factors associated with an increased risk of cesarean delivery included older maternal age, shorter maternal height, greater body mass index, greater weight gain during pregnancy, older gestational age, hypertension, diabetes mellitus, and initial cervical dilation less than 3 cm. A nomogram was constructed based on the final model with a bias-corrected c-index of 0.709 (95% confidence interval 0.671-0.750).
  
  
  CONCLUSIONS
  We identified independent risk factors that can be used to predict cesarean delivery among nulliparous women undergoing induction of labor at term. If validated in other populations, the nomogram could be useful for individualized counseling of women with a combination of identifiable antepartum risk factors.
  
  
  METHODS
  II.
authors.affiliation: Department of Obstetrics and Gynecology and the Department of Health Sciences Research, Divisions of Biomedical Statistics and Informatics and Epidemiology, Mayo Clinic, Rochester, Minnesota; and the Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Mary Catherine
authors.initials: MC
authors.lastname: Tolcher
authors.forename: Michael R
authors.initials: MR
authors.lastname: Holbert
authors.forename: Amy L
authors.initials: AL
authors.lastname: Weaver
authors.forename: Michaela E
authors.initials: ME
authors.lastname: McGree
authors.forename: Janet E
authors.initials: JE
authors.lastname: Olson
authors.forename: Sherif A
authors.initials: SA
authors.lastname: El-Nashar
authors.forename: Abimbola O
authors.initials: AO
authors.lastname: Famuyide
authors.forename: Brian C
authors.initials: BC
authors.lastname: Brost
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007751:Labor, Induced / Q000009:adverse effects / Q000706:statistics & numerical data*; D049451:Nomograms; D010298:Parity; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D047929:Term Birth; D017211:Treatment Failure; D055815:Young Adult