title: Trial of labor or repeat cesarean delivery in women with morbid obesity and previous cesarean delivery.
abstract: OBJECTIVE
  Assess effects of body mass index (BMI) on trial of labor after previous cesarean delivery and determine whether morbidly obese women have greater maternal and perinatal morbidity with trial of labor compared with elective repeat cesarean delivery.
  
  
  METHODS
  Secondary analysis from a prospective observational study included all term singletons undergoing trial of labor after previous cesarean delivery. Body mass index groups were as follows: normal 18.5-24.9, overweight 25.0-29.9, obese 30.0-39.9, morbidly obese 40.0 kg/m2 or greater, and were compared for failure and maternal and neonatal morbidities. The morbidly obese trial of labor and elective repeat cesarean delivery were compared for maternal and neonatal morbidities. Multivariable logistic regression analysis controlled for confounding variables.
  
  
  RESULTS
  There were 14,142 trial of labor participants and 14,304 elective repeat cesarean delivery participants. Increasing BMI was directly associated with failed trial of labor after previous cesarean delivery: from 15.2% in normal weight (1,344) to 39.3% in morbidly obese (1,638), with combined risk of rupture/dehiscence increasing from 0.9% to 2.1% in morbidly obese women. Among morbidly obese women, trial of labor carried greater than five-fold risk of uterine rupture/dehiscence (2.1% versus 0.4%), almost a two-fold increase in composite maternal morbidity (7.2% versus 3.8%) and five-fold risk of neonatal injury (1.1% versus 0.2%) (fractures, brachial plexus injuries, and lacerations), but no neonatal encephalopathy. Morbidly obese women failing a trial of labor had six-fold greater composite maternal morbidity than those undergoing a successful trial of labor (14.2% versus 2.6%).
  
  
  CONCLUSIONS
  Body mass index correlates with outcomes in trial of labor after previous cesarean delivery. Morbidly obese women undergoing a trial of labor were at increased risk for failure. Increased BMI was associated with greater composite morbidity and neonatal injury compared with elective repeat cesarean delivery, but absolute morbidities were small. Increased risks should be considered before trial of labor after previous cesarean delivery.
  
  
  METHODS
  II-2.
authors.affiliation: Department of Obstetrics and Gynecology, University of Chicago, Chicago, Illinois 60612, USA. jhibbar@uic.edu
authors.forename: Judith U
authors.initials: JU
authors.lastname: Hibbard
authors.forename: Sharon
authors.initials: S
authors.lastname: Gilbert
authors.forename: Mark B
authors.initials: MB
authors.lastname: Landon
authors.forename: John C
authors.initials: JC
authors.lastname: Hauth
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Leveno
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Margaret
authors.initials: M
authors.lastname: Harper
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Menachem
authors.initials: M
authors.lastname: Miodovnik
authors.forename: Marshall
authors.initials: M
authors.lastname: Carpenter
authors.forename: Alan M
authors.initials: AM
authors.lastname: Peaceman
authors.forename: Mary J
authors.initials: MJ
authors.lastname: O'Sullivan
authors.forename: Baha M
authors.initials: BM
authors.lastname: Sibai
authors.forename: Oded
authors.initials: O
authors.lastname: Langer
authors.forename: John M
authors.initials: JM
authors.lastname: Thorp
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ramin
authors.forename: Brian M
authors.initials: BM
authors.lastname: Mercer
authors.forename: Steven G
authors.initials: SG
authors.lastname: Gabbe
mesh_terms: D000328:Adult; D015992:Body Mass Index; D017604:Cesarean Section, Repeat / Q000009:adverse effects / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D009767:Obesity, Morbid / Q000150:complications*; D007744:Obstetric Labor Complications / Q000209:etiology; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome; D011446:Prospective Studies; D014219:Trial of Labor; D016064:Vaginal Birth after Cesarean / Q000706:statistics & numerical data