Can You Have a VBAC?
For women who've been screened properly and deemed fit for a VBAC, the success rate is between 60 and 80 percent, according to the American College of Obstetricians and Gynecologists (ACOG). There are several medical factors that physicians consider when assessing your situation.
What type of incision was made on your uterus during your previous c-section?
This is the key factor in deciding if you can deliver vaginally. There are three types of incisions used during c-sections: low transverse (a side-to-side cut made on the lower part of the uterus), which is the most widely used; low vertical (an up-and-down incision made in the lower part of the uterus); and high vertical or "classical" (an up-and-down cut made in the upper part of the uterus), which was once commonly used but is now reserved for extreme emergencies.
Though every incision leaves a scar, certain uterine scars are more likely to rupture during a VBAC. Classical incisions are most likely to rupture, so women with these are advised not to attempt a VBAC. The best VBAC candidates are those with low transverse incisions.
What was the reason for your previous c-section?
This can tell your doctor a lot about your chances of delivering vaginally. If your c-section was due to something physicians wouldn't expect to repeat, such as the fact that baby was breech or his heartbeat was irregular, then you have a good chance of having a successful VBAC without complications, says Iffath Hoskins, MD, chair of obstetrics and gynecology at Lutheran Medical Center, in Brooklyn, New York. However, if you had a c-section because your cervix did not dilate adequately or the baby's head did not descend, or both, your chance of a successful VBAC is somewhat lower. Likewise, according to research Dr. Hoskins has conducted, the further along a woman was during her first labor when she needed a c-section, the less likely she'll have a successful vaginal birth in her second labor. In addition, if you're carrying a larger baby, your doctor may determine that a VBAC is too risky.
Are both you and your unborn baby healthy?
If the fetus's health is unstable or if there are complications, such as your child being in a breech position, you can't have a VBAC. Your health is also considered, because conditions such as diabetes and high blood pressure can make VBAC riskier. If problems arise during labor, a c-section can still be performed quickly and safely. In fact, ACOG guidelines state that a physician capable of performing a c-section should be present during every VBAC delivery. For this reason, home births aren't recommended for moms-to-be attempting a VBAC.
Too many c-sections?
ACOG's latest guidelines say that VBAC is a safe option for women who have had only one cesarean, provided their doctor feels they're good candidates. Even if you wanted to try a VBAC after having two c-sections, it might be hard to find a doctor to do it.
What type of labor do you want?
Recent studies have shown that the rate of uterine rupture is lower when labor begins spontaneously; also, the use of prostaglandin gel (applied to the cervix to encourage dilation) can increase your risk of rupture. For this reason, doctors will usually not induce labor for a VBAC.