[Factors associated with mode of delivery among primipara women with one previous cesarean section and undergoing a trial of labor].
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.
Matias
Jacinta Pereira
JP
Departamento de Tocoginecologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, SP.
Parpinelli
Mary Angela
MA
Cecatti
José Guilherme
JG
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