I am seven weeks away from my due date with my second child. With my first I had a C-section and hopefully will have a VBAC this time. I have heard about the minute possibility of uterine rupture. If I am planning for a VBAC, would using an epidural mask any signs of rupture or other things being wrong? Is there any extra risk from an epidural in my case?

--Becky

The risk of uterine rupture in labor after a prior cesarean section is quite low -- for the most common type of cesarean section incision (low transverse) it ranges between 0.2-1.5 percent. Uterine rupture can be catastrophic to both mother and baby, and death of both may occur. For this reason, all VBAC (vaginal birth after cesarean) attempts should be done in a hospital, with most authorities on the subject recommending continuous fetal heart rate and contraction monitoring. Most often, uterine rupture is diagnosed by the onset of a nonreassuring fetal heart rate -- fetal distress, in other words. Sometimes severe abdominal pain, different from the pain of labor, will develop, or the baby may all of a sudden be higher in the pelvis than it was before, or heavy vaginal bleeding may begin. Any of these signs demands an immediate cesarean section to achieve the best outcome.

Epidurals can be used in women who are attempting a VBAC. The overall success rate for VBACs is around 70 percent, but varies widely depending on the reason for the initial cesarean. The success rates is similar regardless of whether an epidural is used. Epidurals do not appear to mask the signs of uterine rupture if it should occur. Some obstetricians, however, feel more comfortable inserting an intrauterine pressure catheter in all woman attempting a VBAC who receive an epidural. Others may place a pressure catheter into the uterus only in women who are also receiving oxytocin (Pitocin) to augment their labor; still others feel an intrauterine pressure catheter should only be used in women whose labor is not progressing normally.

You should discuss your desire to have an epidural with your obstetrician now, before you go into labor. You should ask what your doctor's policy is regarding epidural in a woman who has had a prior cesarean and if any special monitoring will be required. The time to find this out is now, and not at 3am when you are in the throes of labor.