Poster Session 2
Mary C. Gallo, MD, PhD
MFM Fellow
University of Rochester
Rochester, NY, United States
Shaun R. Wesley, MD
MFM Fellow
University of Rochester
Rochester, New York, United States
Siddharth Hariharan, MD (he/him/his)
Fellow Physician
University of Rochester
Rochester, New York, United States
Sarah Crimmins, DO
University of Rochester
Rochester, New York, United States
This study aimed to identify key predictors of a successful vaginal birth after cesarean (VBAC) among women with two previous cesarean sections and no prior spontaneous vaginal deliveries (SVD) using US vital statistics natality birth data, and to determine the uterine rupture rate in this population.
Study Design: A retrospective cohort study used data from the US Vital Statistics natality birth dataset. The analysis included women with two previous cesarean sections and no prior SVD. Descriptive statistics were performed on all variables. Logistic regression was used to identify predictors of VBAC success. Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were calculated, and the uterine rupture rate was determined.
Results: The study included 537,852 women, with an overall VBAC success rate of 3.0%. Native Hawaiian or Other Pacific Islander (NHOPI) women had higher odds of VBAC success compared to White women (aOR = 1.38, CI: 1.09-1.75). Women with Class II (aOR = 0.53, 95% CI: 0.46-0.60) and Class III (aOR = 0.43, 95% CI: 0.38-0.49) obesity had significantly lower odds of VBAC success. Women aged 40+ years exhibited lower odds of VBAC compared to women aged under 20 years (aOR = 0.41, 95% CI: 0.31-0.55). Privately insured had higher odds of VBAC success than those with public insurance (aOR = 1.97, 95% CI: 1.84-2.12). There were 536 cases of uterine rupture identified, corresponding to a rate of 0.10%.
Conclusion: This study highlights predictors associated with VBAC success. The overall VBAC success rate was low at 3.0%, a result potentially limited by using a retrospective dataset with many covariates. The finding that privately insured women had better outcomes than those with public insurance may reflect disparities in access to healthcare resources. The finding of increased risk of failure in the highest BMI and age categories continues to support these variables as independent risk factors for cesarean delivery. The reported uterine rupture rate of 0.10% is lower than previous studies, supporting VBAC as a viable option for delivery mode as part of shared decision making.