The VBAC Calculator is a convenient tool for predicting the success rate of a vaginal birth after cesarean (VBAC). The app consists of 3 calculators which use patient-specific data in order to generate a predictive score.
The "Standard" calculator uses the widely-used predictive model published in Grobman, William A., et al., Development of a nomogram for prediction of vaginal birth after cesarean delivery, Obstetrics & Gynecology, volume 109(4), pp. 806-812, 2007. This predictive model uses pre-pregnancy BMI and prior medical history to predict VBAC success rates. It can be used at any time during the term of pregnancy during a clinical visit.
The "Standard + Admission Factors" calculator is a variant of the 2007 Grobman prediction method as found in the following publication: Grobman William A., et al., Does information available at the time of admission for delivery improve prediction of successful birth after cesarean? American Journal of Perinatology, volume 26(10), pp.693-701, 2009. This model uses additional information at time of hospital admission to predict VBAC success rates.
Lastly, the "Simple" calculator also uses information at time of admission (same as the "Standard + Admissions Factors" calculator). The source for this predictive calculator is: Metz, Tori D., et al., Simple, validated vaginal birth after cesarean delivery prediction model for use at the time of admission, Obstetrics & Gynecology, volume 122(3), pp.571-578, 2013. This is a straight-forward prediction method that combines BMI and age information with the well-known Bishop Score calculation to determine VBAC success.
Please note that is app is provided solely for educational purposes and should not be used in lieu of sound, professional medical guidance.