Purpose: to study trial of labor (TOL) for vaginal birth after one previous cesarean section. Methods: this is a retrospective cohort study that included 438 pregnant women with one previous cesarean section and their 450 newborns. They were divided into two groups - with and without TOL. The minimum sample size was 121 pregnant mothers per group. TOL was considered as an independent variable and vaginal birth and maternal and perinatal complication frequency as dependent variables. Both univariate and multivariate analyses were performed. The comparison of observed frequencies (%) was analyzed by the chi-squared test (chi²) with 5% significance, and linear regression from the odds ratio (OR) and confidence interval of 95% (CI95%). Results: TOL was used in 59.2% of vaginal deliveries. It was less used in women over 40 years (2.7% vs 6.7%) and in those with clinical or obstetrical diseases such as arterial hypertension (7.0%) and bleeding in the third trimester (0.3%). There was a higher risk for puerperal complications with cesarean deliveries (OR = 3.53, CI 95% = 1.57-7.93), independent of TOL. Perinatal mortality was dependent on neonatal weight and fetal malformations, not on TOL. Newborns from mothers not submitted to TOL were at a higher risk for developing breathing complications (OR = 1.92 CI 95% = 1.20-3.07). Conclusions: The results confirm that trial of labor after a previous cesarean section is a safe method - assisting vaginal delivery in 59.2% of births and not interfering with maternal and perinatal mortality. It is a treatment that should be stimulated.
Trial of labor; Previous cesarean section; Maternal and perinatal complications
