The Facts About Vaginal Birth After Caesarean
The great myths about VBACs, busted.
In my ob-gyn practice I am often surprised by what women have been told about their bodies. Among patients of reproductive age, there is one myth that is especially rampant: That if a woman has had a c-section, all of her babies must be born the same way. It’s widely thought that a VBAC (vaginal birth after cesarean delivery) is unsafe, because of the risk of uterine rupture along the scar line.
But in an overwhelming majority of cases, nothing could be farther from the truth. Our bodies heal well from surgery, and the uterus offers the most impressive example. Toward the end of a woman’s pregnancy, the lower segment of the uterus—where the cesarean incision is typically made—stretches out like a balloon. It’s so paper-thin the ob-gyn has to be careful not to nick the baby’s skin with her scalpel. After delivery the uterus contracts to its original shape, and just a few months later, there isn't any evidence of weakness in the uterine wall.
The risk of complications with a VBAC is less than 1 percent (similar to the rate of other obstetric emergencies, like cord prolapse). And five years ago, the American Congress of Obstetricians and Gynecologists (ACOG) deemed VBACs safe for most women.
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Still, a new government report found that among women who underwent a cesarean for a previous birth, 90 percent have a repeat c-section, despite the longer recovery time and higher risk of infection.
Why physicians and hospitals hesitate
The c-section rate varies widely across the country—and maternal and fetal variables alone do not explain the differences. Both the ACOG and the National Institutes of Health have suggested that an institutional bias against VBACs might play a role. Some physicians and hospitals don't want to try, for a variety of possible reasons.
One of the most common complaints I hear is that VBACs require the primary provider to be in the hospital and out of her office, where she could be seeing other patients. But the truth is, there are solutions to this problem. Most hospitals have in-house doctors in the labor and delivery unit around the clock.
This is where institutional philosophy becomes so important: If you want to try for a VBAC, you need to make certain that all of the various physicians who could end up caring for you—from your ob-gyn to the other doctors in her call group to the hospital personnel on multiple 12-hour shifts—are committed to supporting you through your labor.
What you should know about VBAC labor
I have performed more than 300 VBACs. These are a few observations and tips from my experience.
If you need to be induced, you can still have a VBAC. In an ideal scenario, you would go into spontaneous labor before 41 weeks. But if that doesn’t happen, don’t give up hope. I have induced labors that ended with successful VBACs, though it’s often a longer process.
Conditions must be right. Near the end of your pregnancy, your doctor will check to see if your baby is a normal size, and that there is an adequate amount of fluid in the amniotic sac. Finally, once you are in labor, a fetal heart rate monitor will be used to assess the baby's condition.
Try to make sure you are in labor before you go to the hospital. It’s possible that although you’re having contractions, your cervix hasn’t begun changing yet. And if you arrive too early, the hospital may send you home. Consult your doctor often, and if need be, go to her office to get checked. Once you are admitted at the hospital, an operating room must be kept available for you until the baby arrives.
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Your labor may be slower than you expected. New guidelines used by most institutions consider a woman to be in active labor once her cervix has dilated to 6 centimeters (as opposed to 4 centimeters). As a result, it can take up to 20 hours to reach this stage. But remember: in labor and delivery, all time ceases to make sense. Let the process happen on its own schedule—and trust your provider. This is why you chose her carefully.
Your odds are good. The ACOG estimates that 60 to 80 percent of VBACs are successful. But on occasion, the three Ps of labor—presentation (fetal position in the birth canal), power (the strength of contractions), and pelvis (the structure of the bones)—don’t work in a woman’s favor. If you end up giving birth by cesarean, don’t be discouraged. Life is not always predictable. The point is you tried, and you and your baby are safe—and that is the outcome we all want.
Lizellen La Follette, MD, is a board certified ob-gyn who runs a private practice specializing in VBACs, menopause, and fertility in Marin County, California.