I love my well educated, experienced commenters. There was a good, lively discussion about catastrophic uterine rupture risk on a recent post about vaginal birth after cesarean (VBAC) attempts. Well, I found a statistic!
According to Lyerly et al:
Although rates of delivery-related perinatal death are indistinguishable between VBAC and primary vaginal delivery, there is a genuine differential in the rate of uterine rupture–related hypoxicischemic encephalopathy. Such perinatal morbidity is indeed devastating. It is also extremely rare. In a recent large prospective study, the probability of this outcome was 0.00046 in infants whose mothers underwent a VBAC trial at term compared with no cases in infants whose mothers underwent repeat cesarean delivery.
Two important points here. Uterine rupture that actually causes perinatal morality has a probability of 0.00046. That is, by all measures, extremely, extremely rare. Also, all causes of perinatal mortality for VBAC were identical to perinatal mortality risk for a first time vaginal delivery.