title: [Factors associated with mode of delivery among primipara women with one previous cesarean section and undergoing a trial of labor].
abstract: OBJECTIVE
  To identify factors associated with cesarean section in women with only one previous delivery by cesarean section and undergoing a trial of labor.
  
  
  METHODS
  A retrospective cross sectional study was performed from 1986 to 1998 including a total of 1746 women with one prior cesarean section and delivering after a trial of labor. Cases with a current twin pregnancy or with malformation incompatible with life were excluded. Women were divided in two groups according to the mode of the second delivery: Cesarean (n=731) or Vaginal Birth After Cesarean (VBAC, n=1015). To identify factors associated to the mode of delivery, the prevalence ratios (PR) and the 95%CI for each isolated factor, adjusted according to age, were assessed. In each analysis, cases with missing information were excluded.
  
  
  RESULTS
  The total rate of Vaginal Birth After Cesarean was 58.1%. The factors significantly associated with cesarean section were: higher maternal age, greater fundal height (PR 1.5; 95%CI 1.19-1.88), premature rupture of membranes (1.3; 1.08-1.54), amniotic fluid with an altered aspect (1.22; 1.04-1.43) or volume (1.32; 1.01-1.73), altered fetal heart rate (1.96; 1.68-2.28), non cephalic presentation (2.03; 1.54-2.66), induction of labor (1.74; 1.42-2.11) and no labor analgesia (2.57; 2.11-3.11).
  
  
  CONCLUSIONS
  The factors associated with cesarean section were older age, non-cephalic presentation, premature rupture of membranes, signs of large fetus, the need of induction of labor and signs of compromised fetal wellbeing.
authors.affiliation: Departamento de Tocoginecologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, SP.
authors.forename: Jacinta Pereira
authors.initials: JP
authors.lastname: Matias
authors.forename: Mary Angela
authors.initials: MA
authors.lastname: Parpinelli
authors.forename: José Guilherme
authors.initials: JG
authors.lastname: Cecatti
mesh_terms: D000328:Adult; D017604:Cesarean Section, Repeat; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D010298:Parity; D011247:Pregnancy; D012189:Retrospective Studies; D014219:Trial of Labor; D016064:Vaginal Birth after Cesarean