Validation of the MFMU Network VBAC Calculators at an Academic Institution [19S]

• Published in: Obstetrics and gynecology (New York. 1953) Vol. 133 Suppl 1; no. 1; p. 207S
• Main Authors: Rasiah, Stephen S, Reilly, Devin M, Maines, Jaimie L, Thomas, Holly J, Pauli, Jaimey M, Ural, Serdar H
• Format: Journal Article
• Language: English
• Published: by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved 01-05-2019
• ISSN: 0029-7844; 1873-233X
• DOI: 10.1097/01.AOG.0000559471.93644.33

INTRODUCTION:The MFMU Network has developed two calculators to help predict the vaginal delivery success rate of a trial of labor after cesarean section. The purpose of this study was to validate the use of these calculators at an academic institution.
METHODS:This retrospective cohort study compared actual and predicted VBAC success rates with the online MFMU VBAC calculators. Participants were then divided into two groups based on low (<70%) and high (>70%) predicted success.
RESULTS:Preliminary data analysis included 299 patients. 223 (75%) patients had a successful VBAC. The VBAC success rate based on information at the initiation of prenatal care was 59% (predicted=58% P=.92) in the ʼlow successʼ cohort and was 82% (predicted=83% P=.69) in the ʼhigh successʼ cohort. The VBAC success rate based on information from admission for delivery was 26% (predicted=44% P=.12) in the ʼlow successʼ cohort and was 78% (predicted=96% P<.001) in the ʼhigh successʼ cohort.
CONCLUSION:The model was accurate when it incorporated data at the initiation of prenatal care. However, based on information from admission for delivery, the ʼlow successʼ cohort showed a non-significant trend towards lower observed success rates, while the ʼhigh successʼ cohort showed a statistically significant trend towards lower observed success rates. The next step in this project is to determine what factors may be contributing to the decreased accuracy of the ʼadmission for deliveryʼ calculator. In addition, further studies are needed to see if there may be a role for changing counseling to incorporate information from these calculators.