What are the contraindications for a patient wanting to have a VBAC (Vaginal birth after cesarean)?

Choice A rationale A history of uterine rupture in a previous pregnancy is a definitive contraindication for a Trial of Labor After Cesarean (TOLAC) or VBAC. This is because a prior rupture significantly weakens the myometrium, leading to an unacceptably high risk of recurrence (estimated around 6%) during a subsequent labor attempt, which can result in catastrophic maternal and fetal morbidity or mortality. Choice B rationale One previous low transverse cesarean section (LTCS) is actually considered the most favorable prior uterine incision for a VBAC attempt. This type of incision involves the non-contractile lower uterine segment and is associated with the lowest risk of uterine rupture during a subsequent TOLAC (estimated <1%), thus it is a criterion for appropriateness, not a contraindication. Choice C rationale A low-risk pregnancy is a prerequisite for considering a VBAC. Factors such as fetal size (estimated weight <4000 g), single gestation, and no recurrent indications for cesarean section contribute to a favorable prognosis. Therefore, a low-risk pregnancy is an indication, not a contraindication, for a TOLAC. Choice D rationale A previous cesarean section for a non-recurrent indication like breech presentation is considered a favorable factor for VBAC success. Since the indication for the prior cesarean (fetal malpresentation) is no longer present, the chance of a successful vaginal delivery is similar to that of a pregnant person without a prior cesarean, making it an indication, not a contraindication.