Trial of Labor After C-Section (TOLACs) at Northwestern Central DuPage Hospital

Background: Successful vaginal delivery after a C-Section (VBAC) has shown to have lowest morbidity rates for expecting mothers with a history of C-Section. However, a failed trial of labor after a C-Section (TOLAC) has a higher risk of maternal morbidity than a scheduled repeat C-Section. A failed TOLAC leads to a higher risk of uterine scar dehiscence and higher chance of uterine rupture during labor. The differences between morbidity creates a need for physicians to accurately assess which patients would be good candidates for a TOLAC and which patients would be better candidates for an elective repeat C-Section. Another motivation to identify good candidates for TOLAC is to avoid multiple surgeries on patients. Patients with three or more C-Sections have a higher risk of complications, such as hemorrhage, bladder or bowel incontinence, or placenta accreta disorders. Successful VBACs open the door for other possible VBACs in the future. This study aimed to look at TOLACs within the Northwestern Medicine Central DuPage Hospital (NMCDH) system to assess the quality of care at NMCDH compared to the national averages and to assess if any specific variables were better at predicting successful VBACs. Methods: A retrospective chart review was performed. Patients studied were those who delivered at NMCDH between 4/1/2022 and 3/31/2023. There were 2703 deliveries. Of these, Epic parameters were used to remove patients with primary C Sections and first pregnancies because by definition they could not be TOLACs. There were 1699 patients in this group. After this, 1699 charts were manually reviewed to identify 114 TOLAC patients. The following data was then collected on TOLAC patients: bishop score, VBAC success score, BMI Pre-Gravida (if unavailable then estimated pre gravida weight or gravida weight), maternal age, uterine rupture, uterine scar dehiscence, type of labor, and additional comments/complications. Results: Of the 114 TOLACs, 87 patients at CDH had successfully VBAC and 27 had failed. 1 out of the 114 patients had a delivery complicated by uterine rupture. Unknown how many patients had uterine scar dehiscence due to inconsistent documentation. 52 patients were in spontaneous labor, of which 43 successfully VBAC, and 9 failed TOLAC. The remaining 62 patients were induced and 48 successfully VBAC, while 14 failed TOLAC. Conclusions: With a successful VBAC rate of 76% and a uterine rupture of 1%, NMCDH performed well compared to national averages in delivering TOLAC care. The sample size being limited to n=114 limited statistical analysis and any further conclusions. With a larger sample size, conclusions about spontaneous labor vs. induction of labor. BMI, VBAC success scores, and other parameters in TOLAC patients can be assessed.