Do Epidurals Lead to Greater VBAC Success?

I’m 40 years old and 30 weeks pregnant with my second boy. Yay! I had a C-section at 37 years old with my first. My doctor suggested an epidural with my VBAC [vaginal birth after cesarean] this time, in case I need an emergency C-section. I really don’t want one because I want to move around during labor, and I’m nervous it could result in labor arrest and needing an otherwise preventable C-section. But I read that women who get epidurals are 4.5 times more likely to have a successful VBAC. How valid is this? I also read epidurals used to be banned by some hospitals in the case of VBACs, and epidurals could mask signs of uterine rupture. I’ve seen a Swedish study that shows a correlation between length of labor and rate of uterine ruptures. Could you help me make sense of all this?

—VBAC but not at all costs

You’re correct that the evidence here is a little bit all over the place. The issue is some combination of limited data and lack of randomization. That is to say: an ideal study here would randomize women undergoing a trial of labor to use an epidural or not, and evaluate outcomes. This is a difficult study to do (most people do not want their pain relief randomized), and the most severe outcomes, like uterine rupture, are very rare. That’s fortunate for pregnant women, but it means you would need a huge sample size to detect differences.

In the better data we do have (meta-analysis; this paper), the evidence is largely neutral. Epidural use doesn’t seem to have a strong impact on uterine rupture. In some of these data, it appears that those who use epidurals have a lower risk of cesarean, but it is possible that this is reflecting other differences across the populations.

The bottom line is that from the standpoint of success and the major safety concerns, the data isn’t pushing strongly in one way or another. I should also say, many epidurals do let you walk around, and the impacts on labor timing are quite small.

However: the major consideration to add to this is the one your doctor has articulated. If you do end up needing an emergency C-section, having had an epidural means they’re less likely to need to use a general anesthesia. In the end, that is the consideration you have to weigh against the desire not to have an epidural.