title: Trial of labor in patients with a previous cesarean section: does maternal age influence the outcome?
abstract: OBJECTIVE
  This study was undertaken to evaluate the effect of maternal age on the rate of vaginal delivery and the rate of uterine rupture in patients undergoing a trial of labor (TOL) after a prior cesarean delivery.
  
  
  METHODS
  A cohort study of all women with a live singleton fetus undergoing a TOL after a previous low-transverse cesarean delivery was performed between 1988 and 2002 in a tertiary care center. Patients were divided into 3 groups according to maternal age: less than 30 years old, 30 to 34 years old, and 35 years or older. Women with no prior vaginal delivery and with at least 1 prior vaginal delivery were analyzed separately. The rate of vaginal delivery and the rate of symptomatic uterine rupture were calculated. Multivariate logistic regression analyses were performed to adjust for potential confounding variables.
  
  
  RESULTS
  Of the 2493 patients who met the study criteria, there were 1750 women without a prior vaginal delivery (659, 721, and 370, respectively) and 743 women with a prior vaginal delivery (199, 327, and 217, respectively). The rate of uterine rupture was comparable between the groups (2.0%, 1.1%, 1.4%, P=.404 and 0%, 0.3%, 0.9%, P=.312). Successful vaginal delivery was inversely related to maternal age (71.9%, 70.7%, 65.1%, P=.063, and 91.5%, 91.1%, 82.9%, P=.005). After adjusting for confounding variables, maternal age equal to or greater than 35 years old was associated with a lower rate of successful vaginal delivery in patients without prior vaginal delivery (odds ratio [OR] 0.73, 95% CI: 0.56-0.94), and in patients with a prior vaginal delivery (OR: 0.47, 95% CI: 0.29-0.74).
  
  
  CONCLUSIONS
  Patients who are 35 years or older are more prone to have a failed TOL after a prior cesarean delivery.
authors.affiliation: Department of Obstetrics and Gynecology, Hôpital Ste-Justine and Université de Montréal, Montreal, Quebec, Canada. ebujold@med.wayne.edu
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bujold
authors.forename: Ahmad O
authors.initials: AO
authors.lastname: Hammoud
authors.forename: Israel
authors.initials: I
authors.lastname: Hendler
authors.forename: Susan
authors.initials: S
authors.lastname: Berman
authors.forename: Sean C
authors.initials: SC
authors.lastname: Blackwell
authors.forename: Louise
authors.initials: L
authors.lastname: Duperron
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Gauthier
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008423:Maternal Age; D008499:Medical Records; D011247:Pregnancy; D011256:Pregnancy Outcome; D018566:Pregnancy, High-Risk; D011792:Quebec / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D014219:Trial of Labor; D014597:Uterine Rupture / Q000453:epidemiology* / Q000209:etiology; D016064:Vaginal Birth after Cesarean