title: Effect of gestational age at the prior cesarean delivery on maternal morbidity in subsequent VBAC attempt.
abstract: OBJECTIVE
  The purpose of this study was to estimate the effect of gestational age at the time of prior cesarean on maternal morbidity in women attempting vaginal birth after cesarean delivery (VBAC).
  
  
  METHODS
  A retrospective cohort study of women attempting VBAC, comparing women with a prior cesarean delivery < or = 34 completed weeks to women with a prior cesarean delivery > 34 weeks. The primary outcome was maternal morbidity, including uterine rupture. Univariable, stratified, and multivariable analyses were used to estimate the effect of a prior cesarean performed at < or = 34 weeks on maternal morbidities.
  
  
  RESULTS
  Of 19,474 women with 1 prior cesarean, 12,535 attempted VBAC and 508 of those had a previous cesarean < or = 34 weeks. Study groups had similar risks of uterine rupture (adjusted OR [AOR], 1.5; 95% CI, 0.7-3.5; P = .32) and composite morbidity (AOR, 0.9; 95% CI, 0.5-1.8; P = .81).
  
  
  CONCLUSIONS
  Prior cesarean delivery at < or = 34 weeks' gestation does not appear to increase the risk of maternal morbidity in a subsequent VBAC attempt.
authors.affiliation: Department of Obstetrics and Gynecology, Washington University in St. Louis School of Medicine, St. Louis, MO, USA.
authors.forename: Lorie M
authors.initials: LM
authors.lastname: Harper
authors.forename: Alison G
authors.initials: AG
authors.lastname: Cahill
authors.forename: David M
authors.initials: DM
authors.lastname: Stamilio
authors.forename: Anthony O
authors.initials: AO
authors.lastname: Odibo
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Peipert
authors.forename: George A
authors.initials: GA
authors.lastname: Macones
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data*; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000453:epidemiology*; D009017:Morbidity; D015999:Multivariate Analysis; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D047928:Premature Birth / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D014597:Uterine Rupture / Q000453:epidemiology*; D016064:Vaginal Birth after Cesarean / Q000706:statistics & numerical data*; D055815:Young Adult