title: Predictors of failed trial of labor among women with an extremely obese body mass index.
abstract: OBJECTIVE
  The purpose of this study was to examine predictors associated with cesarean delivery (CD) among extremely obese women undergoing a trial of labor (TOL).
  
  
  METHODS
  Using a delivery database, we identified all pregnant women delivering at our institution from Jan. 1, 2008, through July 31, 2010, weighing >275 lb at the time of delivery who attempted a TOL with a singleton gestation >34 weeks' gestation. Demographic and obstetrical factors were compared for those having a successful vaginal delivery to those having a CD.
  
  
  RESULTS
  During the study period, there were 357 pregnant women who weighed >275 lb (all with body mass index [BMI] >40 kg/m(2)), and among these, 248 (69.5%) attempted a TOL. Women having a CD had a greater BMI (51.6 vs 49.9 kg/m(2), P = .038), were less likely to be parous (32.2% vs 65.8%, P < .0001), and were more likely to be induced (80.5% vs 57.8%) compared to those having a vaginal delivery. Using a multivariable logistic regression model, among nulliparous women, maternal age, parity, and cervical dilation at time of admission were independent predictors for CD. Furthermore, an increase in BMI of 10 kg/m(2) was associated with a 3.5 increased odds (P = .002) for CD.
  
  
  CONCLUSIONS
  Among nulliparous extremely obese women attempting a TOL, BMI was an independent predictor of CD, with the rate of CD increasing further with increasing BMI. The underlying mechanisms for failed TOL in the setting of maternal obesity remain largely unknown.
authors.affiliation: Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC.
authors.forename: Ravindu P
authors.initials: RP
authors.lastname: Gunatilake
authors.forename: Michael P
authors.initials: MP
authors.lastname: Smrtka
authors.forename: Benjamin
authors.initials: B
authors.lastname: Harris
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Kraus
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Small
authors.forename: Chad A
authors.initials: CA
authors.lastname: Grotegut
authors.forename: Haywood L
authors.initials: HL
authors.lastname: Brown
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002585:Cesarean Section / Q000706:statistics & numerical data*; D036861:Delivery, Obstetric / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007751:Labor, Induced / Q000706:statistics & numerical data*; D016015:Logistic Models; D009657:North Carolina; D009765:Obesity / Q000150:complications* / Q000175:diagnosis; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology*; D012307:Risk Factors; D014219:Trial of Labor
keywords: body mass index; labor; obesity; pregnancy; vaginal delivery