An 80% chance of uterine rupture? No way! Where did you read that? If women with prior cesareans had an 80% chance of uterine rupture with a vaginal delivery, any responsible healthcare provider would advise women who undergo c-sections never to get pregnant again. There's always the chance, after all, that you will go into labor and not get to the hospital in time. The rates that i've seen for uterine rupture in vbac women with a low transverse scar (meaning, you were cut side to side low on your belly, not top to bottom) are less than one-quarter of one percent. There are other reasons why a v-bac might not succeed. For instance, the problem that led to your previous c-section might recur. Or your doctor might be so cautious and hesitant to attempt a v-bac that he or she pretty much sets you up for failure before you begin. The fact that you've had four vaginal deliveries already, and even one since your c-section, speaks very well of your chances at doing a vaginal birth this time.
Anyway, sources. I-can is the international cesarean awareness network, and they have an excellent website. Here is their fact sheet on vbac:
http://www.Ican-online.Org/resources/white
_papers/wp_vbac_fact.Htm
here is the webmd section on v-bac, which is a good overview of the mainstream, medical approach to v-bac.
Http://my.Webmd.Com/hw/being_pregnant/hw20
0560.Asp
even if you attempt a v-bac and end up with a c-section anyway, the attempt carries its own benefits for you and your baby. It's much better to undergo a trial of labor that ends with a c-section than it is to schedule your c-section in advance without ever going into labor. For one thing, if you actually begin labor, you know it's time for your baby to be born. You don't have to worry about underdevelopment and the risk of respiratory infections is lower. Also, some research shows that the actual "stress" of labor is not so much stressful for the baby as it is stimulating. It gets them ready to be born and face the world, gets their systems ready to operate independently. Plus the hormones that are released during labor help promote healing, bonding, and other benefits for mom and baby, even after a cesarean delivery.