title: Previous preterm cesarean delivery and risk of subsequent uterine rupture.
abstract: OBJECTIVE
  To determine if women with a history of a previous preterm cesarean delivery experienced an increased risk of subsequent uterine rupture compared with women who had a previous nonclassic term cesarean delivery.
  
  
  METHODS
  A prospective observational study was performed in singleton gestations that had a previous nonclassic cesarean delivery from 1999 to 2002. Women with a history of a previous preterm cesarean delivery were compared with women who had a previous term cesarean delivery. Women who had both a preterm and term cesarean delivery were included in the preterm group.
  
  
  RESULTS
  A prior preterm cesarean delivery was significantly associated with an increased risk of subsequent uterine rupture (0.58% compared with 0.28%, P<.001). When women who had a subsequent elective cesarean delivery were removed (remaining n=26,454) women with a previous preterm cesarean delivery were still significantly more likely to sustain a uterine rupture (0.79% compared with 0.46%, P=.001). However, when only women who had a subsequent trial of labor were included, there was still an absolute increased risk of uterine rupture, but it was not statistically significant (1.00% compared with 0.68%, P=.081). In a multivariable analysis controlling for confounding variables (oxytocin use, two or more previous cesarean deliveries, a cesarean delivery within the past 2 years, and preterm delivery in the current pregnancy), patients with a previous preterm cesarean delivery remained at an increased risk of subsequent uterine rupture (P=.043, odds ratio 1.6, 95% confidence interval 1.01-2.50) compared with women with previous term cesarean delivery.
  
  
  CONCLUSIONS
  Women who have had a previous preterm cesarean delivery are at a minimally increased risk for uterine rupture in a subsequent pregnancy when compared with women who have had previous term cesarean deliveries.
authors.affiliation: Department of Obstetrics and Gynecology at Christiana Care Health System, Newark, Delaware 19713, USA. asciscione@christianacare.org
authors.forename: Anthony C
authors.initials: AC
authors.lastname: Sciscione
authors.forename: Mark B
authors.initials: MB
authors.lastname: Landon
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Leveno
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: Cora
authors.initials: C
authors.lastname: Macpherson
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Dwight J
authors.initials: DJ
authors.lastname: Rouse
authors.forename: Atef H
authors.initials: AH
authors.lastname: Moawad
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Margaret
authors.initials: M
authors.lastname: Harper
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Menachem
authors.initials: M
authors.lastname: Miodovnik
authors.forename: Carpenter
authors.initials: C
authors.lastname: Marshall
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
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002585:Cesarean Section / Q000009:adverse effects*; D005260:Female; D006801:Humans; D016017:Odds Ratio; D011247:Pregnancy; D047928:Premature Birth; D011446:Prospective Studies; D014597:Uterine Rupture / Q000209:etiology*