Safety and success rate of vaginal birth after two cesarean sections: retrospective cohort study

Cesarean section is a lifesaving procedure with short and long-term consequences. Growing rates of cesareansections worldwide arise problems for subsequent birth. The aim of this study was to compare safety of vaginal birthafter two cesarean sections with repeat third cesarean section to help healthcare providers and patients make well informeddecisions about mode of subsequent delivery.

This was a retrospective cohort study conducted in a tertiary reference hospital. Database of alldeliveries (2010-2017) after two previous cesarean sections was created from electronic and paper medical records. Pretermdeliveries, abnormal karyotype and neonates with congenital anomalies were excluded from the study. The final analysisincluded 412 cases for maternal outcome analysis and 406 cases for neonatal outcome analysis.

Trial of labor after two cesareans in comparison to repeat cesarean section increases the risk of hemorrhage(OR: 10.84) and unfavorable composite maternal outcome (OR: 2.58). Failed trial of labor increases this risk of hemorrhage(OR: 15.27) and unfavorable composite maternal outcome (OR: 4.59) even further. There were no significant differences in neonataloutcomes. 22 out of 35 trials of labor ended in successful delivery giving a success rate of 62.85%. 5 of 7 labor inductionsended in repeat cesarean section giving 28.6% success rate. There were no maternal deaths and emergency hysterectomies.

Trial of labor, especially failed trial of labor, is associated with an increased risk of perinatal complications.