title: Maternal and perinatal outcomes associated with a trial of labor after prior cesarean delivery.
abstract: BACKGROUND
  The proportion of women who attempt vaginal delivery after prior cesarean delivery has decreased largely because of concern about safety. The absolute and relative risks associated with a trial of labor in women with a history of cesarean delivery, as compared with elective repeated cesarean delivery without labor, are uncertain.
  
  
  METHODS
  We conducted a prospective four-year observational study of all women with a singleton gestation and a prior cesarean delivery at 19 academic medical centers. Maternal and perinatal outcomes were compared between women who underwent a trial of labor and women who had an elective repeated cesarean delivery without labor.
  
  
  RESULTS
  Vaginal delivery was attempted by 17,898 women, and 15,801 women underwent elective repeated cesarean delivery without labor. Symptomatic uterine rupture occurred in 124 women who underwent a trial of labor (0.7 percent). Hypoxic-ischemic encephalopathy occurred in no infants whose mothers underwent elective repeated cesarean delivery and in 12 infants born at term whose mothers underwent a trial of labor (P<0.001). Seven of these cases of hypoxic-ischemic encephalopathy followed uterine rupture (absolute risk, 0.46 per 1000 women at term undergoing a trial of labor), including two neonatal deaths. The rate of endometritis was higher in women undergoing a trial of labor than in women undergoing repeated elective cesarean delivery (2.9 percent vs. 1.8 percent), as was the rate of blood transfusion (1.7 percent vs. 1.0 percent). The frequency of hysterectomy and of maternal death did not differ significantly between groups (0.2 percent vs. 0.3 percent, and 0.02 percent vs. 0.04 percent, respectively).
  
  
  CONCLUSIONS
  A trial of labor after prior cesarean delivery is associated with a greater perinatal risk than is elective repeated cesarean delivery without labor, although absolute risks are low. This information is relevant for counseling women about their choices after a cesarean section.
authors.affiliation: Department of Obstetrics and Gynecology at Ohio State University, College of Medicine and Public Health, Columbus 43210-1228, USA. landon.1@osu.edu
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: Sharon
authors.initials: S
authors.lastname: Leindecker
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
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: 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 Jo
authors.initials: MJ
authors.lastname: O'Sullivan
authors.forename: Baha
authors.initials: B
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: D000293:Adolescent; D000328:Adult; D001803:Blood Transfusion / Q000706:statistics & numerical data; D017604:Cesarean Section, Repeat / Q000009:adverse effects*; D004716:Endometritis / Q000209:etiology; D005260:Female; D005313:Fetal Death / Q000453:epidemiology; D006801:Humans; D020925:Hypoxia-Ischemia, Brain / Q000453:epidemiology / Q000209:etiology; D007044:Hysterectomy / Q000706:statistics & numerical data; D007226:Infant Mortality; D007231:Infant, Newborn; D016015:Logistic Models; D007744:Obstetric Labor Complications; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D012306:Risk; D014219:Trial of Labor; D014592:Uterine Hemorrhage / Q000209:etiology / Q000601:surgery; D014597:Uterine Rupture / Q000453:epidemiology / Q000209:etiology* / Q000601:surgery; D016064:Vaginal Birth after Cesarean / Q000009:adverse effects* / Q000706:statistics & numerical data