Many moms who've experienced a C-section with their first child enter subsequent pregnancies with the hope of avoiding the same procedure when labor day arrives. But due to the increased possibility of uterine rupture at the site of the previous C-section (which happens in fewer than 1 percent of
VBACs), a VBAC (vaginal birth after cesarean) is often considered high risk by doctors.
To understand why, we need to get into the nitty-gritty of C-sections.
If a uterine rupture results in excessive bleeding, a woman may have to undergo a blood transfusion or an emergency hysterectomy, explains William Grobman, M.D., associate professor of obstetrics and gynecology at Northwestern University's Feinberg School of Medicine, in Chicago. And the outcome can be life-threatening to the baby, although that only happens in one out of every 1,000 to 2,000 VBAC attempts. Fortunately, about 60 to 80 percent of women who attempt a VBAC are able to give birth vaginally -- and recent recommendations from the National Institutes of Health reiterated that VBACs can be as safe as normal births.
Before determining whether you can try for a VBAC, your doctor will give your case careful consideration. One important factor: the reasoning behind your previous C-section. If it resulted from something that isn't likely to reoccur, such as a breech baby, your chances of being able to attempt a VBAC are higher than if your C-section was due to an issue that could reemerge, such as not dilating. Ultimately, it's up to your physician to decide what's safe, but the more categories you fit into here, the more likely it is that a VBAC will be a real possibility for you.
If you've given birth twice, but only the second was a C-section, you have a lower risk for uterine rupture, says Brian Mercer, M.D., professor of obstetrics and gynecology at Case Western Reserve University School of Medicine, in Cleveland. Why? "Your body has demonstrated that it can complete labor," he explains, so you're more likely to be able to do it again.
If so, your doctor probably made a horizontal (transverse) incision across the lower part of your uterus, which heals well. (You'll need your hospital report for confirmation, since the scar that counts is the one on your uterus, not your skin.) But if you had an emergency C-section, your doctor may have made a vertical cut on your uterus. This rules out a VBAC, as the resulting scar generally doesn't heal well enough to endure labor.
Tell your doctor, since having more than two cesareans may be riskier than attempting a VBAC, as the chance of surgical complications increases with the number of C-sections a woman has. The most serious risk: placenta accreta, where the placenta abnormally adheres to the lining of the uterus. This can lead uncontrollable bleeding and might require a hysterectomy.
If you were slim when you became pregnant and haven't gained a lot of weight since, your chances of a problem-free VBAC are higher. "Being overweight doesn't rule one out, but the increase of soft tissue around the pelvis may make it harder for a baby to come through the birth canal," says Brian Mercer, M.D., professor of obstetrics and gynecology at Case Western Reserve University School of Medicine, in Cleveland.
Though doctors aren't sure why, older patients have a lower chance of having a successful VBAC than younger women. There are lots of theories about this, says David Stamilio, M.D., associate professor of obstetrics and gynecology at Washington University School of Medicine, in St. Louis: "It could be that as women age, they tend to have larger babies, or their muscles are not as conditioned--no one really knows."
Going into spontaneous labor before 41 weeks is a good thing if you're hoping for a VBAC. "Women who carry a baby more than a week beyond their due date are about 33 percent less likely to deliver vaginally," explains David Stamilio, M.D., associate professor of obstetrics and gynecology at Washington University School of Medicine, in St. Louis. Inducing labor can also significantly reduce your VBAC odds. Women who are induced are two times as likely to end up requiring another C-section than those who go into labor on their own.
Small community hospitals may have a no-VBAC policy if they can't afford to have an anesthesiologist or obstetrician available 24 hours a day. But if you're a low-risk candidate, your doc may refer you to an ob-gyn who practices at an institution where VBACs are routine. This doctor can help you decide if you can get to the hospital quickly enough once labor begins -- and if a traditional birth can be a part of your birth plan.
Copyright © 2010 Meredith Corporation.
All content, including medical opinion and any other health-related information, is for informational purposes only and should not be considered to be a specific diagnosis or treatment plan for any individual situation. Use of this site and the information contained herein does not create a doctor-patient relationship. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.