The factors that might increase the success of VBAC would be a mom who's already had a Vaginal delivery. Many moms might have a vaginal delivery and for whatever reason have a c-section on their second or third baby. If they've already had a successful vaginal delivery, their success for VBAC is going to be greater than someone who's never had a vaginal delivery. If there's a non-repeating indication, again, that if the first baby was breech, now this baby is head down, she's probably a good candidate for a VBAC.
It's also there are some variables that are related to a patient's age. The older we are, the less likely success. If you actually had a previous labor where you stopped dilating, or your baby stopped descending, then that decreases the chance of success. Maternal weight could have an indicator too that might decrease. The heavier you are, the more difficult it might be to have a successful VBAC.
