Mayo Clinic Health Library

VBAC: Insight from a Mayo Clinic specialist

Updated: 11-06-2012
Photo of Roger Harms, M.D.
Roger W. Harms, M.D.

Years ago, a C-section ended any hope of future vaginal deliveries. Today, however, many women are candidates for vaginal birth after cesarean (VBAC). Still, the choice to pursue VBAC or schedule a repeat C-section can be tough.

Here's insight from Roger W. Harms, M.D., an obstetrician at Mayo Clinic, Rochester, Minn., and medical editor-in-chief of MayoClinic.com.

Why would a woman consider VBAC?

The risks associated with a vaginal delivery are lower than the risks associated with a C-section overall — as long as you can deliver the baby at a facility equipped to handle a C-section in case of emergency — and the recovery time is faster. VBAC might also be appealing if you have an emotional investment in a vaginal delivery or a desire to experience natural childbirth.

It's also important to consider future pregnancies. If you've had one C-section and you're certain this is your last delivery, the difference in risk between VBAC and a second C-section is probably minimal. However, if you're planning more pregnancies in the future, VBAC becomes a better option with each subsequent delivery.

What are the risks of VBAC?

For about 25 percent of women who attempt VBAC, labor ends in a repeat C-section. This is known as a failed trial of labor after cesarean.

If you must have a repeat C-section after labor has begun, you face a slightly higher risk of C-section complications, such as a uterine infection. The most concerning risk of VBAC, however, is uterine rupture — when the baby breaks through the wall of the uterus into the mother's abdominal cavity.

If your uterus ruptures, an emergency C-section is needed to prevent life-threatening complications, including heavy bleeding and infection for the mother and brain damage for the baby. In some cases, the uterus might need to be removed (hysterectomy) to stop the bleeding. If your uterus is removed, you won't be able to get pregnant again.

Can you put the risk of uterine rupture into perspective?

Uterine rupture is rare, affecting fewer than 1 out of 100 women who've had a prior low transverse uterine incision — the most common type for a C-section. Still, it's possible. And naturally, the risk of uterine rupture causes concern.

If you're considering VBAC, what's important is to make sure that the facility where you'll deliver the baby is ready to deal with that complication. You'll need staff immediately available to provide emergency care.

Who's eligible for VBAC?

VBAC eligibility depends on many factors. For example:

  • Have you had previous vaginal deliveries? A vaginal delivery at least once before or after your prior C-section increases the odds of a successful VBAC.
  • What type of uterine incision was used for the prior C-section? Scars left from certain types of incisions have an increased risk of tearing during labor and delivery.
  • What prompted the prior C-section? If your prior C-section was done for a reason that isn't present during your current pregnancy — such as the baby's position in your uterus — you might be a good candidate for VBAC.
  • How many C-sections have you had? You might be a less suitable candidate for VBAC if you've had multiple C-sections.
  • When was your last C-section? The risk of uterine rupture is higher if you attempt VBAC too soon after having a C-section — such as within 18 to 24 months.
  • Are you delivering multiples? VBAC might be possible with twins if the lower twin is in the headfirst position, but VBAC generally isn't an option for triplets or other multiples.
  • Do you have any health conditions that might affect a vaginal delivery? Although research isn't conclusive, some studies suggest that chronic conditions such as diabetes, heart disease or high blood pressure could reduce the chances of successful VBAC. If you have an infection that could be passed to your baby during vaginal delivery — such as genital herpes or HIV — a C-section might be the best option.
  • Will you deliver the baby in a facility equipped to handle an emergency C-section? A home delivery isn't appropriate for VBAC.

If you had a uterine rupture during a previous pregnancy, you're not a candidate for VBAC. Likewise, VBAC should be approached with extreme caution if you need medication to induce labor.

How does labor and delivery during VBAC differ from labor and delivery during a routine vaginal birth?

The actual physiology of labor and delivery is the same, but the precautions taken during labor are different. You and your baby will be closely monitored, and the medical team will be less tolerant of abnormal labor patterns. Your doctor will be prepared to do a repeat C-section if needed.

Some women are outspoken supporters of VBAC, while others are outspoken against it. What should a woman believe?

There's always a cohort of people within the population who adopt positions with a great deal of enthusiasm and vigor, often based on their own experiences. Still, it isn't possible to extrapolate the experience of one person to the experience of another.

If you're considering VBAC, don't be swayed by extremes. Make your decision based on the facts and your personal values and beliefs.

What other advice do you offer women who are considering VBAC?

If you're considering VBAC, discuss the option with your health care provider early in pregnancy.

Find out about the VBAC policy at the facility where you'll deliver your baby, but keep flexibility in mind. You won't know what cards you'll be dealt until labor begins. The circumstances of your labor could make VBAC a clear choice — or you and your doctor might quickly decide that a repeat C-section would be best after all.

If you choose a scheduled C-section, you'll never see what cards were in the deck — and for some women, that might be just fine.

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