Trial of labor after cesarean (TOLAC) happens when a woman attempts to give birth vaginally after a previous C-section. Here’s what expectant parents need to know. 

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If you've already had a baby by cesarean section, it doesn't rule out the possibility of vaginal birth for your next pregnancy. You’ll first need a trial of labor after cesarean (TOLAC) to attempt the delivery. If everything goes as planned, the TOLAC will result in a vaginal birth after cesarean (VBAC). A failed TOLAC leads to a subsequent cesarean.

TOLAC Facts and Statistics 

TOLAC and VBAC weren’t common in the United States prior to 1980. However, studies showed that the rate of emergency C-section wasn't any higher for those giving birth by VBAC, which caused the popularity to rise quickly. It hit an all-time high in 1991.

Unfortunately, this drastic increase in the number of VBACs led to less effective screening to determine which women were truly eligible for vaginal birth. Serious complications, such as uterine rupture (a tearing of the incision from the previous cesarean), began to occur more often. According to Roger Freeman, M.D., director of obstetrics and gynecology at Long Beach Memorial Medical Center, in California, this has made doctors more hesitant about VBACs.

Today's attitude toward VBAC seems to be cautiously optimistic. So while fewer VBACs are being performed, they are much safer, and doctors are now evaluating patients more carefully.

TOLAC vs VBAC: What’s the Difference?

TOLAC (trial of labor after cesarean) happens when a woman attempts to give birth vaginally after C-section. TOLACs that fail usually lead to an emergency C-section, while successful TOLACs end in vaginal birth.

The VBAC success rate is between 60 and 80 percent, as long as the woman has gotten the go-ahead from her doctor, according to the American College of Obstetricians and Gynecologists (ACOG). “VBAC is a safe and reasonable option for most women and is in fact safer than repeat C-section for many,” says  Marilynn Frederiksen, M.D., an associate professor of clinical obstetrics and gynecology at the Feinberg Medical School of Northwestern University and a member of s panel of childbirth experts convened by the National Institutes of Health (NIH). 


Attempting a TOLAC increases a woman's risk for certain complications, including uterine rupture. The good news is that these complications are relatively rare. In fact, past research from Ohio State University Medical Center (the largest study ever done on the safety of VBAC) found that the current risk of developing a serious complication during a VBAC is about 1 in 2,000.

Additionally, a failed TOLAC leads to a higher risk of a postoperative infection compared with the risk for women who deliver by scheduled cesarean, says Dr. Hoskins. For many expectant moms, these negative aspects are enough reason to opt for a scheduled C-section.

On the flip side, repeat C-sections also carry certain risks, such as placenta accreta, in which the placenta adheres abnormally to the uterine wall. And, of course, a C-section involves major abdominal surgery, which makes you susceptible to the associated risks, such as bleeding, infection, or blood clots in your legs or lungs. With a vaginal birth, you'll spend less time in the hospital, and your recovery period will be two weeks as opposed to six weeks or longer.

Should I Attempt a TOLAC?

Women should get the go-ahead from the doctor before attempting TOLAC. There are several medical factors that physicians consider when assessing your situation.

Type of C-section incision. 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); 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). Though every incision leaves a scar, vertical ones are more likely to rupture during a VBAC. The best candidates are those with low transverse incisions.

Reason for your previous C-section. If your C-section was due to something physicians wouldn't expect to repeat, such as breech presentation or irregular heartbeat, then you have a high chance of a successful VBAC without complications, says Iffath Hoskins, M.D., 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, 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.

The health of the mother and fetus. If the fetus 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.

The number of previous C-sections. ACOG's 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.

Type of labor. 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.

Note that 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.

TOLAC Guidelines for a Successful VBAC

While a vaginal birth isn't guaranteed after TOLAC—sometimes a C-section is necessary for the health and safety of the mom and baby—there are some steps you can take to help boost your odds. Here are strategies to consider for a successful TOLAC experience.

Educate yourself. It pays to educate yourself about the potential risks and rewards of this method of delivery. Luckily, there are plenty of places for expectant moms to turn, such as prenatal VBAC classes, health care providers, and even other VBAC moms.

Find a supportive health care provider. Finding a provider who is supportive of VBACs and has a proven success rate is of the utmost importance, explains Larry Leeman, M.D., professor of family medicine/obstetrics and gynecology and co-medical director of The University of New Mexico Hospital's Mother Baby Unit. "It's important to know if your doctor or midwife is likely to be attending your planned VBAC and to be sure that his or her partner or covering physicians are also supportive of VBAC," he says.

When interviewing prospective doctors and midwives, be sure to ask what Dr. Leeman calls "revealing" questions. For example, if you go past your due date or have a medical need for labor induction, will your physician and hospital support the choice of induction, or does that mean a VBAC is no longer an option? What is the successful VBAC rate in his or her practice as well as the hospital you plan to birth in?

Make sure your hospital is VBAC-friendly. Even if your health care provider supports your wish for a VBAC, the hospital where you plan to deliver may not. According to a 2009 report from the International Cesarean Awareness Network, more than 40 percent of U.S. hospitals do not allow moms to deliver vaginally after a cesarean.

Hire a doula. Enlisting the help of a designated non-medical labor support person is not only great for pain management but can also drastically reduce the rates of cesareans that are not medically necessary. A 2014 report published in The American Journal of Managed Care discovered that having the continuous support of a doula throughout the birthing process reduced a woman's chances of a non-indicated C-section by as much as 80 percent.