Topic Overview

What is a vaginal birth after caesarean (VBAC)?

If you have had a caesarean birth (also called a C-section) before, you may be able to deliver your next baby vaginally. This is called vaginal birth after caesarean, or VBAC. You can also think about having another C-section, sometimes called a repeat caesarean or an Elective Repeat Caesarean Section (ERCS).

Most people who have had 1 previous C-section can have a VBAC. Talk to your doctor or midwife and use the information below to make the choice that is right for you.

If you and your doctor or midwife agree to try a VBAC, you will have what is called a "trial of labour after caesarean," or TOLAC. This means that you plan to go into labour with the goal to deliver vaginally. But as in any labour, it is hard to know if a VBAC will work. You still may need a C-section. About 1 out of 4 people who have a trial of labour need to have a C-section. This means about 3 out of 4 people who have a TOLAC deliver vaginally.^{footnote 1}Both TOLAC and C-sections are safe options for most people.

Is a trial of labour (TOLAC) safe?

A TOLAC and VBAC can be a safe choice for most people. 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 or midwife will review your medical history, look at risk factors in your current pregnancy, and talk about your risk for having problems during a trial of labour.

If you choose a VBAC, you and your baby will be closely monitored. As with any labour, if you or your baby show signs of complications, a caesarean section may be done.

What are the benefits of a TOLAC and VBAC?

Having a vaginal birth is associated with the lowest overall risk of complications. 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. Learn more about the risks of a repeat C-section below.
• Less pain after delivery.
• Fewer days in the hospital and a shorter recovery at home.
• A more active role for you and your birthing partner in the birth of your child.

What are the risks of TOLAC and VBAC?

A TOLAC and VBAC can be a safe choice for most people.
If you had a previous C-section, there is a small chance that your C-section scar (uterine scar) could come open during labour. If this happens, you will get an emergency C-section. The risk that a scar will tear open is very low during VBAC when you have just one low caesarean scar and your labour is not started with medicine.

Is VBAC Right for You?

Having a vaginal birth after having a C-section can be a safe choice for most people. But it can have risks for both you and your 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 or midwife 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

About 3 out of 4 people who choose VBAC are able to have a vaginal birth. About 1 in 4 people may need a repeat C-section. The likelihood of a successful vaginal birth after caesarean (VBAC) is influenced by many things, including having access to a supportive healthcare provider who has experience with VBAC.

Some healthcare providers use VBAC calculators to help identify factors that might impact VBAC. But these calculators are not good at predicting whether or not you will have a successful labour.
Your chances of a successful VBAC are higher when:^{footnote 2}

• Your care provider has experience with VBAC.
• Your previous C-section was done because your baby was breech, or for a condition or situation (like high blood pressure or pre-eclampsia) that you do not have in your current pregnancy.
• You have had a vaginal delivery or a successful VBAC before.
• Your labour 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 care provider does not have a lot of experience supporting VBAC.
• Your labour is induced.
• Your labour is augmented (medicine given to make labour stronger once it has already started).
• Your previous caesarean was because of a difficult, non-progressing labour, which is called dystocia.
• Your body mass index (BMI) is greater than 30.
• You are older than 35.
• Your baby is estimated to be very large [bigger than 4000 g (9 lb)].
• You are beyond 40 weeks of pregnancy.
• You have pre-eclampsia.

VBAC can be considered for pregnancies with twins.

Risks of VBAC and Caesarean Deliveries

Overall, a routine vaginal delivery is less risky than a routine caesarean, which is a major surgery. But if you have a caesarean scar on your uterus, you have a slight risk of the scar breaking open during labour. This is called uterine rupture.

Risks of VBAC

The risks of VBAC include:

• Problems during labour that result in a caesarean delivery. This occurs with about 25 out of 100 people who try VBAC. But it doesn't happen with 75 out of 100 people who try VBAC.^{footnote 3}
• Rupture of the scar on the uterus, which is rare but can be deadly to the baby. About 5 out of 1000 people have a uterine rupture during a trial of labour.^{footnote 3} A vertical incision used in a past C-section, use of certain medicines to start (induce) labour, 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.
• A uterine rupture can increase your chance of a hysterectomy, increase your chance of needing a blood transfusion, and can cause death for your baby.

Risks of any caesarean

Most births that happen by C-section will go well.
The risks of caesarean delivery include:

• Infections.
• Pain.
• 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).

When deciding whether to have another caesarean birth, it’s important to think about how many children you plan on having in the future. Having had a previous C-section increases the chance of problems in future pregnancies. Each added C-section 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 you and your baby and can raise your risk of needing a blood transfusion or hysterectomy to stop bleeding.

Examinations 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 labour is a safe option may include:

• A review of surgery records to verify the type of incision used for a previous caesarean.
• A fetal ultrasound.
• Fetal heart monitoring, which is also used during labour 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. You might notice bleeding and pain.

What To Expect

Information, preparation, and teamwork are needed for a successful vaginal birth after caesarean (VBAC).

Childbirth and VBAC education

To prepare for labour, consider taking a childbirth education class at your local hospital or clinic. You and your birthing partner can learn:

• What to expect during labour 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.

Labour

Other than requiring closer monitoring, trial of labour after caesarean, or TOLAC labour, is the same as normal labour. During early labour, you can remain as active and mobile as you want. There are no specific recommendations for TOLAC until active labour begins. During the active period of labour, continuous fetal heart monitoring is recommended to watch for early signs of fetal heart rate abnormalities or uterine rupture. (For more information, see Examinations and Tests.)

If you are attempting a trial of labour and you have not had a previous vaginal birth or your previous caesarean was done early on in labour, your labour will be like a first-time labour.

Medicines for starting or strengthening a trial of labour

As the end of pregnancy nears, the cervix normally becomes soft and begins to open (dilate) and thin (efface), preparing for labour and delivery. If you or your baby have complications, your doctor or midwife may recommend that instead of waiting for labour to start on its own, that your labour be induced (started with medicine).

Some doctors and midwives avoid the use of any medicine to start (induce) a trial of labour, because they are concerned about uterine rupture. Other doctors and midwives are comfortable with the careful use of oxytocin to start labour when the cervix is soft and opening (dilating).

If your labour slows or stops progressing, your doctor or midwife may use oxytocin to strengthen (augment) contractions.

Pain medicine

As with most vaginal births, most people who choose VBAC can safely use pain medicine during labour.

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:

Recovery

Vaginal birth after caesarean (VBAC) recovery is similar to recovery after any vaginal birth. After a vaginal delivery, you and your baby can usually go home within 24 to 48 hours. By comparison, recovery from a caesarean 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 caesarean deliveries. Before you leave the hospital, you will receive a list of signs of infection to watch for in the first few weeks after delivery.