title: Labor outcomes with increasing number of prior vaginal births after cesarean delivery.
abstract: OBJECTIVE
  To estimate the success rates and risks of an attempted vaginal birth after cesarean delivery (VBAC) according to the number of prior successful VBACs.
  
  
  METHODS
  From a prospective multicenter registry collected at 19 clinical centers from 1999 to 2002, we selected women with one or more prior low transverse cesarean deliveries who attempted a VBAC in the current pregnancy. Outcomes were compared according to the number of prior VBAC attempts subsequent to the last cesarean delivery.
  
  
  RESULTS
  Among 13,532 women meeting eligibility criteria, VBAC success increased with increasing number of prior VBACs: 63.3%, 87.6%, 90.9%, 90.6%, and 91.6% for those with 0, 1, 2, 3, and 4 or more prior VBACs, respectively (P<.001). The rate of uterine rupture decreased after the first successful VBAC and did not increase thereafter: 0.87%, 0.45%, 0.38%, 0.54%, 0.52% (P=.03). The risk of uterine dehiscence and other peripartum complications also declined statistically after the first successful VBAC. No increase in neonatal morbidities was seen with increasing VBAC number thereafter.
  
  
  CONCLUSIONS
  Women with prior successful VBAC attempts are at low risk for maternal and neonatal complications during subsequent VBAC attempts. An increasing number of prior VBACs is associated with a greater probability of VBAC success, as well as a lower risk of uterine rupture and perinatal complications in the current pregnancy.
  
  
  METHODS
  II.
authors.affiliation: Department of Obstetrics and Gynecology at Case Western Reserve University-MetroHealth Medical Center, Cleveland, Ohio 44109-1989, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Mercer
authors.forename: Sharon
authors.initials: S
authors.lastname: Gilbert
authors.forename: Mark B
authors.initials: MB
authors.lastname: Landon
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Leveno
authors.forename: Dwight J
authors.initials: DJ
authors.lastname: Rouse
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Atef H
authors.initials: AH
authors.lastname: Moawad
authors.forename: Hyagriv N
authors.initials: HN
authors.lastname: Simhan
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
authors.initials: A
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
mesh_terms: D000328:Adult; D001034:Apgar Score; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D008428:Maternal Mortality; D007744:Obstetric Labor Complications / Q000453:epidemiology*; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D012307:Risk Factors; D014219:Trial of Labor; D014597:Uterine Rupture / Q000453:epidemiology*; D016064:Vaginal Birth after Cesarean / Q000009:adverse effects* / Q000706:statistics & numerical data*