A prospective study of a new prediction model of Vaginal Birth After Cesarean section at a tertiary care centre

Aims and Objective: This study was undertaken to create a new and simple model for predicting likelihood of vaginal birth after caesarean section using variables available at the time of admission.
Methods: A prospective observational study was done at tertiary care centre in Haryana over a period of 12 months (January 2018 - December 2018) in pregnant women attending labor room with previous one cesarean section fulfilling criteria for undergoing trial of labour after cesarean (TOLAC) and sample size taken was 150. A Vaginal birth after cesarean (VBAC) score was calculated for each patient using a new prediction model which included variables available at time of admission such as maternal age, gestational age, bishop’s score, body mass index, indication of primary cesarean section and clinically estimated fetal weight. The results of the VBAC score were correlated with the outcome i.e. successful VBAC or failed VBAC. Chi square test and student’s t test was used for comparison among the groups. Descriptive and regression analysis was done for the study variables.
Results: Out of 150 TOLAC cases, 78% had successful VBAC and rest 22% had failed VBAC. The observed probability of having a successful VBAC for a VBAC score of 0-3 was 34%, 4-6 was 68%, 7-9 was 90% and ≥ 10 was 97%. The prediction model performed well with area under the curve (AUC) of 0.77 (95% CI 0.68 to 0.85) of the receiver operating characteristics (ROC) curve.
Conclusion: The present study shows that the proposed VBAC prediction model is a good tool to predict the outcome of trial of labour after cesarean and can be used to counsel women regarding the mode of delivery in current and subsequent pregnancies. Further studies of this model and other such models with different permutations and combinations of variables are required.