The Failure Rate, Related Factors, and Neonate Complications of Vaginal Delivery after Cesarean Section

The rate of Cesarean Section (CS) is high in Iran. A successful Vaginal Birth After Cesarean (VBAC) section can protect mothers against the risk of having multiple CS. This study aimed to evaluate the success rate of VBAC, related factors, and the causes of failure.

This cross-sectional study was conducted on 150 pregnant women who were candidates for VBAC and admitted at maternity hospitals in Qom from 2016 to 2018. The required data were collected from the patients' records and entered into the checklist. Then, the success rate of VBAC was estimated, and related factors together with the causes of failure were determined by t-test, Chi-square, and independent-samples t-tests in SPSS v. 18 software.

The mean (SD) maternal age was 32 (5.20) years and ranged from 21 to 45 years old. The success rate of VBAC was estimated to be 85.33%, and 14.67% of the patients had to repeat a CS after failure in vaginal delivery. The mean time between previous CS and present delivery was statistically significant between successful and failure groups (t ₁₂₅ = 2.32, p = 0.002). The results also revealed that the most important causes of VBAC failure were prolonged labor [odds ratio (OR) = 4.70)], full arrest (OR = 2.70), and decline fetal heart (OR = 5.31).

The success rate of VBAC in our study was high. However, VBAC was more successful when the interval between inter-deliveries was long, and lower complications were reported when the interval was 2-4 years.