VBAC ( vaginal birth after caesarean section): Is normal delivery after c- section possible?

VBAC (Vaginal Birth After Caesarean): Is a Normal Delivery After a C-Section Possible?

By Dr. Anuradha Narayanan

Consultant Obstetrician & Gynaecologist | Anurag Women Health Care, Chembur, Mumbai

For many women, having a Caesarean section (C-section) during their first pregnancy raises an important question during their next pregnancy:

“Can I have a normal delivery this time?”

The answer is yes—for many women, a Vaginal Birth After Caesarean (VBAC) is a safe and successful option. However, not every woman is a suitable candidate. The decision depends on several medical factors and should always be made after a thorough evaluation by your obstetrician.

What is VBAC?

VBAC (Vaginal Birth After Caesarean) refers to delivering a baby vaginally after having had one previous Caesarean section.

Instead of planning another C-section, eligible women can undergo a Trial of Labour After Caesarean (TOLAC). If labour progresses safely, it results in a successful VBAC.

Is VBAC Safe?

Yes.

According to international guidelines from ACOG, RCOG, and WHO, VBAC is considered a safe option for carefully selected women.

The success rate ranges between 60% and 80%, and is even higher in women who have previously had a vaginal delivery.

Who is a Good Candidate for VBAC?

You may be eligible if you have:

✅ One previous lower segment (transverse) Caesarean section

✅ No previous uterine rupture

✅ A healthy singleton pregnancy

✅ Baby in head-down position

✅ No placenta previa

✅ No major medical complications requiring Caesarean delivery

✅ A hospital equipped for emergency Caesarean if needed

Those are important additions. Current evidence suggests that scar thickness and the interval since the previous Caesarean should be considered alongside the overall clinical picture, although no single ultrasound measurement should be used as the sole determinant for offering or denying VBAC.

Additional Criteria for Selecting Women for VBAC

1. Lower Uterine Segment (LUS) Scar Thickness

Ultrasound assessment of the previous Caesarean scar, usually performed in the third trimester (34–38 weeks), can provide additional information about the integrity of the uterine scar.

Although there is no universally accepted cut-off, studies suggest:

* LUS thickness >3.5 mm: Associated with a low risk of uterine rupture and generally considered reassuring.

* LUS thickness 2.5–3.5 mm: Intermediate zone. VBAC may still be considered after individualized counselling and assessment of other risk factors.

* LUS thickness <2.5 mm: Associated with a higher risk of scar dehiscence or uterine rupture. Many obstetricians recommend an elective repeat Caesarean section in these cases.

It is important to note that scar thickness should not be the only criterion for deciding on VBAC. The measurement can vary depending on the ultrasound technique, whether the full or myometrial thickness is measured, and the operator’s experience. Decisions should always incorporate the woman’s obstetric history, current pregnancy, and the availability of emergency obstetric care.

2. Interval Since the Previous Caesarean Section

The time between the previous Caesarean and the current delivery significantly influences scar healing.

* Less than 18 months: Increased risk of uterine rupture. VBAC is generally approached with caution.

* 18–24 months: Acceptable for many women if there are no additional risk factors.

* More than 24 months: Considered ideal, with better scar healing and a higher likelihood of successful VBAC.

Many obstetricians prefer an interval of at least 18–24 months between deliveries before recommending a trial of labour.

Other Factors That Improve VBAC Success

Women are more likely to have a successful VBAC if they have:

* One previous lower segment transverse Caesarean section

* Previous vaginal delivery (especially a previous successful VBAC)

* Spontaneous onset of labour

* Estimated fetal weight less than 2.8-3.0 kg

* Cephalic (head-down) presentation

* No placenta previa or other contraindications to vaginal birth

* No significant maternal medical complications

* Delivery planned in a hospital with facilities for continuous fetal monitoring and 24-hour emergency Caesarean section

Expert Advice

A successful VBAC depends on careful patient selection, close intrapartum monitoring, and timely intervention when necessary. While scar thickness and the interval since the last Caesarean are valuable considerations, they should complement—not replace—comprehensive clinical judgement and shared decision-making between the woman and her obstetrician.

Clinical note: Neither the American College of Obstetricians and Gynecologists (ACOG) nor the Royal College of Obstetricians and Gynaecologists (RCOG) recommends using ultrasound scar thickness alone to determine eligibility for VBAC. It should be interpreted in the context of the patient’s complete clinical profile.

When is VBAC Not Recommended?

Your doctor may advise a repeat Caesarean if you have:

* Previous classical (vertical) uterine incision

* Previous uterine rupture

* Two or more complicated Caesareans (depends on individual case)

* Placenta previa

* Certain fetal positions such as transverse lie

* Large baby with additional risk factors

* Multiple obstetric complications

Every pregnancy is unique, and your obstetrician will discuss the safest option.

Benefits of VBAC

1. Faster Recovery

Women usually recover more quickly after vaginal birth than after surgery.

2. Less Pain

There is generally less postoperative pain and reduced need for pain medication.

3. Lower Risk of Surgical Complications

VBAC avoids risks associated with surgery, including:

* Excessive bleeding

* Infection

* Injury to surrounding organs

* Anaesthesia-related complications

4. Shorter Hospital Stay

Most mothers return home sooner following a successful VBAC.

5. Better Bonding with Baby

Earlier mobility often helps mothers initiate breastfeeding and skin-to-skin contact sooner.

6. Fewer Risks in Future Pregnancies

Multiple Caesarean sections increase the risk of:

* Placenta accreta

* Placenta previa

* Dense abdominal adhesions

* Surgical complications

A successful VBAC may reduce these risks in future pregnancies.

What are the Risks of VBAC?

Although VBAC is generally safe, it does carry some risks.

The most important is:

Uterine Rupture

This occurs when the previous Caesarean scar opens during labour.

Fortunately, this is uncommon, occurring in approximately 0.5 -0.9% (about 1 in 200 to 1 in 111 women) of women with one previous low-transverse Caesarean scar and 0.9 to 1.8% (about 1 in 111 to 1 in 56 women)in previous two cesarean section.

Because of this possibility, VBAC should only be attempted in hospitals capable of performing an emergency Caesarean section if required.

Factors That Increase the Risk

• Induction of labour, especially with prostaglandins

• Augmentation with high-dose oxytocin

• Inter-delivery interval of less than 18 months

• Thin lower uterine segment scar (<2.5 mm)

• Previous uterine rupture

• Classical (vertical) or T-shaped uterine incision

• Multiple previous uterine surgeries (e.g., extensive myomectomy)

How is Labour Managed During VBAC?

During labour, doctors carefully monitor:

* Baby’s heart rate

* Mother’s vital signs

* Progress of labour

* Scar tenderness

* Signs of uterine rupture

Continuous fetal monitoring is usually recommended.

If any concerns arise, an emergency Caesarean is performed promptly.

Can Labour be Induced?

Induction is possible in selected cases but requires careful consideration.

Some induction medications can increase the risk of uterine rupture. Your obstetrician will choose the safest method based on your individual circumstances.

Factors that Increase VBAC Success

Women are more likely to have a successful VBAC if they:

* Had a previous vaginal birth

* Went into labour naturally

* Have a normal BMI

* Have a baby of average size

* Are younger than 40 years

* Had the previous Caesarean for a non-recurring reason (such as breech presentation or fetal distress)

How Should You Prepare for a VBAC?

* Attend all antenatal visits.

* Discuss your previous Caesarean records with your doctor.

* Maintain a healthy weight.

* Stay physically active if advised.

* Eat a balanced, nutritious diet.

* Deliver at a hospital with 24-hour emergency obstetric services.

* Be flexible—your birth plan should prioritize the safety of both mother and baby.

• should be mentally prepared for additional risk of uterine rupture although small if carefully monitored.

• Chances of repeat section if required

Common Myths About VBAC

Myth: Once a Caesarean, always a Caesarean.

Fact: This is no longer true. Many women safely deliver vaginally after one previous Caesarean.

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Myth: The scar will definitely rupture.

Fact: Uterine rupture is rare in women with a previous low-transverse Caesarean scar.

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Myth: VBAC is dangerous for the baby.

Fact: In appropriately selected women, VBAC has excellent maternal and neonatal outcomes when labour is carefully monitored.

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Myth: Every woman qualifies for VBAC.

Fact: Not everyone is a suitable candidate. Individual assessment is essential.

Frequently Asked Questions

Is VBAC painful?

Labour pain is similar to any vaginal birth. Pain relief options such as epidural analgesia are available and can be safely used during VBAC.

Can I have a VBAC after two Caesareans?

Some women with two previous low-transverse Caesarean sections may be candidates in experienced centres, but the decision must be individualized.

What is the success rate of VBAC?

Approximately 60–80%, depending on individual factors.

Is epidural allowed during VBAC?

Yes. Epidural analgesia is considered safe and does not prevent recognition of complications when appropriate and regress monitoring is in place, but should be avoided in a place which is not equipped as sometimes danger signs can be masked.

A previous Caesarean section does not automatically mean that all future babies must be delivered by Caesarean. For many women, VBAC offers a safe opportunity for a vaginal birth with faster recovery, fewer surgical risks, and improved outcomes for future pregnancies.

The key is careful patient selection, informed decision-making, and delivery in a well-equipped hospital with experienced obstetric care. Discuss your previous delivery, current pregnancy, and birth preferences with your obstetrician to determine whether VBAC is the right choice for you.

Key references:

* ACOG Practice Bulletin No. 205: Vaginal Birth After Cesarean Delivery.

* RCOG Green-top Guideline No. 45: Birth After Previous Caesarean Birth.

* Society of Obstetricians and Gynaecologists of Canada (SOGC) Guideline on TOLAC.