Vaginal Birth After Cesarean Delivery (VBAC) Overview

• For women who have previously delivered babies through C-section, vaginal birth can be a lower-risk, faster-recovery option.
• The principle risk of VBAC is rupture of the scar in the uterus from the prior cesarean delivery. However, this occurs in only about 1 in 500 women who choose to deliver via VBAC.
• Factors determining who is a good candidate for VBAC include both the mother’s and the baby’s overall health during pregnancy, number of prior C-sections, and location and type of incisions from previous cesarean deliveries.

What is VBAC?

In the past, women who have experienced cesarean delivery of babies – also called a C-section – would have little choice but to deliver future babies the same way. Today, however, many women may safely deliver subsequent babies vaginally.

CU Anschutz Women's Health specializes in vaginal birth after cesarean delivery, or VBAC, and has the expertise to handle even the toughest cases, allowing the mother to have her baby delivered using her preferred method.

Advantages of VBAC include:

• No abdominal surgery
• Avoidance of additional uterine scarring
• Lower risk of infection
• Participation of a spouse or partner in the birth process
• Faster recovery and fewer days in the hospital (typically two days for VBAC, compared to four for C-sections)
• Less blood loss
• Lower risks of bowel or bladder injury and certain problems with the placenta
• Each successive C-section gets more complicated for the mother, but each vaginal delivery generally gets easier

Doctors refer to attempted labor through VBAC as trial of labor after cesarean, or TOLAC. The greatest risk of TOLAC is a rupture of the uterine scar left by the previous C-section.

Although rare, uterine scar ruptures can pose serious problems for both mother and baby.

Who is a candidate for VBAC?

Fortunately, the odds of uterine scar rupture during VBAC are only roughly 1 in 500, according to the American College of Obstetricians and Gynecologists (ACOG). The best odds are for women who have only one low C-section scar and whose labor is not induced by medicine.

Other risk factors include the mother’s and baby’s health and the type and location of surgical incision from a previous C-section.

Low, transverse (side to side) incisions are associated with the least risk. High, vertical (up and down) incisions carry the most; ACOG recommends against trying VBAC for women with these incisions from prior births.

Nonetheless, the majority of expectant mothers are candidates for VBAC. Published studies indicate that more than two-thirds of women who have undergone C-sections can successfully deliver through VBAC.

In as many as 40 percent of cases, VBAC candidates develop problems during labor (such as fetal distress) that will ultimately require cesarean delivery, according to ACOG.

For women opting to try VBAC, choosing a hospital and obstetrician with adequate expertise is extremely important. In order to offer VBAC, the hospital should be equipped with medical staff with the right training and the proper equipment to do rapid emergency C-sections at any hour of the day or night.

What to consider before choosing VBAC

• Mother’s general health – Women in good overall health with no major medical problems are better candidates for VBAC than women with conditions such as high blood pressure and diabetes.
• Baby’s health – A single baby of normal size and position whose head is down in the womb reduces vaginal delivery risks.
• Absence of repeated problems – A study published in the ACOG medical journal showed that women who did not experience a repeat of the same problems (such as a baby in breech position, with feet, legs or buttock pointed downward) that led to previous C-sections were just as likely to deliver vaginally successfully as women who had not had previous cesareans.