Vaginal Birth After Cesarean (VBAC)
What is a vaginal birth after cesarean (VBAC)?
If you have had a cesarean delivery (also called a C-section) before, you may be able to deliver your next baby vaginally. This is called vaginal birth after cesarean, or VBAC.
Most women, whether they deliver vaginally or by C-section, don't have serious problems from childbirth.
If you and your doctor agree to try a VBAC, you will have what is called a "trial of labor after cesarean," or TOLAC. This means that you plan to go into labor with the goal to deliver vaginally. But as in any labor, it is hard to know if a VBAC will work. You still may need a C-section. About 25 out of 100 women who have a trial of labor need to have a C-section. This means about 75 out of 100 women who have a TOLAC deliver vaginally.footnote 1
Is a trial of labor safe?
Having a vaginal birth after having a C-section can be a safe choice for most women. Whether it is right for you depends on several things, including why you had a C-section before and how many C-sections you've had. You and your doctor can talk about your risk for having problems during a trial of labor.
A woman who chooses VBAC is closely monitored. As with any labor, if the mother or baby shows signs of distress, an emergency cesarean section is done.
What are the benefits of a TOLAC?
The benefits of a VBAC compared to a C-section include:
- Avoiding another scar on your uterus. This is important if you are planning on a future pregnancy. The more scars you have on your uterus, the greater the chance of problems with a later pregnancy.
- Less pain after delivery.
- Fewer days in the hospital and a shorter recovery at home.
- A lower risk of infection.
- A more active role for you and your birthing partner in the birth of your child.
What are the risks of TOLAC?
The most serious risk of a trial of labor is that a C-section scar could come open during labor. This is very rare. But when it does happen, it can be very serious for both the mother and the baby. The risk that a scar will tear open is very low during VBAC when you have just one low cesarean scar and your labor is not started with medicine. This risk is why VBAC is often only offered by hospitals that can do a rapid emergency C-section.
If you have a trial of labor and need to have a C-section, your risk of infection is slightly higher than if you just had a C-section.
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Is VBAC Right for You?
Having a vaginal birth after having a C-section can be a safe choice for most women. But it can have risks for both the mother and the baby. Whether VBAC is right for you depends on what risk factors (things that increase your risk) you have that could make it unsafe. You and your doctor can decide whether VBAC is right for you.
As with a first-time childbirth, even if you are a good candidate for a successful VBAC, there is no guarantee that you will give birth vaginally and without complications.
What Affects VBAC Success
Pregnancy, labor, and delivery are different for every woman and difficult to predict. Even if your first pregnancy required a cesarean, the next one may not. The likelihood of a successful vaginal birth after cesarean (VBAC) is influenced by many things. Usually a combination of things affects how well or poorly a trial of labor goes.
Your chances of a successful VBAC are best when:footnote 2
- Your previous cesarean was not done for stalled labor.
- You do not have the same condition that led to a previous cesarean (such as a breech, or feet-down, fetus).
- You have had a vaginal delivery or a successful VBAC before.
- Your labor starts on its own and your cervix dilates well.
- You are younger than 35.
Your chances of a successful VBAC are lower when:footnote 2
- Your previous cesarean was because of difficult labor, which is called dystocia. This is especially true if you were fully dilated when you had a cesarean section for dystocia.
- You are obese.
- You are older than 35.
- Your fetus is estimated to be very large [bigger than 4000 g (9 lb)].
- You are beyond 40 weeks of pregnancy.
- Your last pregnancy was less than 19 months ago.
- You have preeclampsia.
VBAC can be considered for pregnancies with twins.
Risks of VBAC and Cesarean Deliveries
Whether you deliver vaginally or by cesarean section, you are unlikely to have serious complications. Overall, a routine vaginal delivery is less risky than a routine cesarean, which is a major surgery. But a pregnant woman who has a cesarean scar on the uterus has a slight risk of the scar breaking open during labor. This is called uterine rupture.
Although rare, uterine rupture can be life-threatening for both mother and baby. So women with risk factors for uterine rupture should not attempt a vaginal birth after cesarean (VBAC).
Risks of VBAC
The risks of VBAC include:
- Problems during labor that result in a cesarean delivery. This occurs with about 25 out of 100 women who try VBAC. But it doesn't happen with 75 out of 100 women who try VBAC.footnote 1
- Rupture of the scar on the uterus, which is rare but can be deadly to the mother and baby. About 5 out of 1000 women have a uterine rupture during a trial of labor.footnote 1 A vertical incision used in a past C-section, use of certain medicines to start (induce) labor, and many scars on the uterus from past C-sections or other surgeries are some of the things that can increase the chance of a rupture.
- The chance of infection. Women who have a trial of labor and end up having a C-section have a higher risk of infection. This means that the risk of infection is lower after vaginal births and after planned cesareans.footnote 2
Risks of any cesarean
The risks of cesarean delivery include:
- Blood loss that requires a blood transfusion.
- Genital or urinary problems.
- Blood clots.
- Risks from anesthesia.
- A longer recovery time.
- Injury to the baby during the delivery. The injury usually isn't serious.
- Breathing problems (respiratory distress syndrome) for the baby after birth if the due date has been miscalculated and a cesarean is done before the baby's lungs are fully developed.
Future risks. If you are planning to get pregnant again, it's important to think about scarring. After you have two C-section scars, each added scar in the uterus raises the risk of placenta problems in a later pregnancy. These problems include placenta previa and placenta accreta, which raise the risk of problems for the baby and your risk of needing a hysterectomy to stop bleeding.
For more information about cesarean risks, see the topic Cesarean Section.
Exams and Tests
Besides the usual prenatal tests, your doctor will take measures to assess whether vaginal delivery is likely to be a safe birthing option for you. (For more information on standard prenatal tests, see the topic Pregnancy.) These extra measures can help you and your doctor make a well-informed decision about your delivery.
Assessments done sometime during the pregnancy to help find out whether a trial of labor is a safe option may include:
- A review of surgery records to verify the type of incision used for a previous cesarean.
- A fetal ultrasound.
- Fetal heart monitoring, which is also used during labor and delivery to watch for fetal distress. Fetal heart monitoring can also help detect a sudden uterine rupture. A rupture is typically followed by a sudden and then ongoing drop in fetal heart rate. The mother might notice bleeding and pain.
What To Expect
Information, preparation, and teamwork are needed for a successful vaginal birth after cesarean (VBAC).
Childbirth and VBAC education
To prepare for labor, consider taking a childbirth education class at your local hospital or clinic. You and your birthing partner can learn:
- What to expect during labor and delivery.
- How to manage the birth using controlled breathing and emotional and physical support.
- What medical pain-control options may be available for a vaginal delivery.
Other than requiring closer monitoring, trial of labor after cesarean, or TOLAC labor, is the same as normal labor. During early labor, a woman can remain as active and mobile as she wants. There are no specific restrictions for TOLAC until active labor begins. During the active period of labor, continuous fetal heart monitoring is done to watch for early signs of fetal distress or uterine rupture. (For more information, see Exams and Tests.)
If you are attempting trial of labor and you have not had a previous vaginal birth or your previous cesarean was done early on in labor, your labor will be like a first-time labor.
For more information about labor and delivery, see the topic Labor and Delivery.
Medicines for starting or strengthening a trial of labor
As the end of pregnancy nears, the cervix normally becomes soft and begins to open (dilate) and thin (efface), preparing for labor and delivery. When labor does not naturally start on its own, labor may be started artificially (induced).
Some doctors avoid the use of any medicine to start (induce) a trial of labor, because they are concerned about uterine rupture. Other doctors are comfortable with the careful use of oxytocin (Pitocin) to start labor when the cervix is soft and opening (dilating).
If your labor slows or stops progressing, your doctor may use oxytocin to strengthen (augment) contractions.
As with most vaginal births, most women who choose VBAC can safely use pain medicine during labor.
Pain medicine usually is started when the cervix has opened (dilated) 3 cm (1.2 in.) to 4 cm (1.6 in.). Types of pain medicines used include:
- Local anesthesia, which numbs the small area where the medicine is injected.
- Epidural anesthesia, which partially or fully numbs the entire lower part of the body. Studies have shown that epidural anesthesia does not increase uterine rupture rates during vaginal birth after cesarean (VBAC) trials of labor.footnote 3
- Opioids (narcotics), which partially relieve pain and help you relax.
Vaginal birth after cesarean (VBAC) recovery is similar to recovery after any vaginal birth. After a vaginal delivery, the mother and baby can usually go home within 24 to 48 hours. By comparison, recovery from a cesarean section requires 2 to 4 days in the hospital and a period of limited activity as the incision heals.
The overall risk of infection is low for both vaginal and cesarean deliveries. But it is lower after a vaginal birth. Before you leave the hospital, you will receive a list of signs of infection to watch for in the first few weeks after delivery.
- Guise JM, et al. (2010). Vaginal birth after cesarean: New insights. Evidence Report (Publication No. 10-E003). Rockville, MD: Agency for Healthcare Research and Quality.
- American College of Obstetricians and Gynecologists (2017). Vaginal birth after cesarean delivery. ACOG Practice Bulletin No. 184. Obstetrics and Gynecology, 130(5): e217–e233. DOI: 10.1097/AOG.0000000000002398. Accessed May 25, 2018.
- Cunningham FG, et al. (2010). Prior cesarean delivery. In Williams Obstetrics, 23rd ed., pp. 565–576. New York: McGraw-Hill.
Current as of: February 23, 2022
Author: Healthwise Staff
Sarah Marshall MD - Family Medicine
Adam Husney MD - Family Medicine
Kathleen Romito MD - Family Medicine
Kirtly Jones MD - Obstetrics and Gynecology
Current as of: February 23, 2022