Predicting success and reducing the risks when attempting vaginal birth after cesarean

The goal of this manuscript is to review the contemporary evidence on issues pertinent to improving the safety profile of vaginal birth after cesarean (VBAC) attempts. Patients attempting VBAC have success rates of 60%-80%, and no reliable method of predicting VBAC failure for individual patients exists. The rate of uterine rupture in all patients ranges from 0.7% to 0.98%, but the rate of uterine rupture decreases in patients with a prior vaginal delivery. In fact, in patients with a prior vaginal delivery, VBAC appears to be safer from the maternal standpoint than repeat cesarean. Inevitably, the obstetrician today will encounter the situation of deciding whether or not to induce a patient with a uterine scar, and particular attention is paid to the success and risks of inducing labor in this patient population. Induction of labor is associated with a slightly lower successful vaginal delivery rate, although the rate remains above 50% in virtually all patient populations. The rate of uterine rupture increases slightly, but still remains around 2%-3%. Although misoprostol use is discouraged due to its association with increased risks of uterine rupture, transcervical catheters, oxytocin, and amniotomy may be used to induce labor in women attempting VBAC.