The Alphabet of Vaginal Birth After Cesarean Delivery

NOTE: This post relates to women who have had one prior Cesarean delivery and a known lower transverse uterine incision.

What do all the letters mean?

CD—Cesarean delivery

TOLAC—Trial of labor after a cesarean. This refers to the process of attempting to have a vaginal delivery after having had a prior CD.

VBAC—Vaginal birth after cesarean. This refers to a successful vaginal delivery after having had a CD.

RCD—Repeat cesarean delivery. This refers to a CD done after having had a prior CD.

ERCD—Elective repeat cesarean delivery. This refers to a patient who has had a prior CD and desires to electively undergo a RCD prior to the onset of labor at or after 39 weeks.

LTCD—Low transverse cesarean delivery. This refers to the incision on the uterus. A low transverse uterine incision is made in the lower segment of the uterus and goes from side-to-side, much like the incision on the skin that goes from side-to-side. However, just because you have a side-to-side incision on your skin does not mean you had the same on your uterus. Some incisions on the uterus go up and down. Some incisions on the skin go up and down. It is important that you know how the incision on your uterus was made after a CD.

Provider—Or obstetrical care provider. In this blog, it refers to an OB/GYN.

How is a TOLAC different from a VBAC?

If you have had a cesarean delivery, you can opt for an ERCD or a TOLAC with the next pregnancy. A ‘TOLAC’ is the process of attempting to have a vaginal delivery after having had a CD. Once a vaginal delivery after a prior CD has occurred, the patient has had a ‘VBAC’.

Do all providers offer their patients VBACs?

Because of the significant complications that can occur, some providers do not offer TOLACs to their patients. In addition, providers may not be able to offer a TOLAC due to the limitations of the hospital or facility in which they are practicing.

For any individual undergoing a TOLAC, continuous fetal heart rate monitoring is required during the labor process. In addition, a provider who is familiar with the signs of uterine rupture and other complications of TOLAC, and who is experienced with managing a patient undergoing a TOLAC, should be present at all times in the hospital. Finally, TOLAC should occur in hospitals equipped to perform an emergent CD if needed. This means that not only does the provider need to be available in the hospital at all times, but anesthesia providers should also be present and available to provide anesthesia for labor during the TOLAC and a CD if needed. Not all hospitals require that the obstetrical care or anesthesia providers be physically present in the hospital. As a result, providers in these hospitals are not able to offer a TOLAC to their patients.

Let your provider know as early as possible if you are thinking about a TOLAC. That way if they do not offer TOLACs, you can be referred to someone who does and you can be counseled on whether you are a good candidate for a TOLAC.

What are the benefits of having a VBAC?

There are many benefits to having a VBAC, including a shorter recovery in most cases, avoiding another abdominal surgery, and lower chance of having infection or extra blood loss. In addition, the desire to have a vaginal delivery, as well as wanting to have more children may play a role in an individual's decision to attempt a TOLAC. Having multiple CDs can be problematic with an increased risk of surgical complications, placental implantation abnormalities, and the potential for hysterectomy.

What are the risks or potential complications of a TOLAC?

Some of the complications of a TOLAC include hemorrhage, infection, and uterine rupture, as well as the increased risks associated when a TOLAC fails and you need a RCD. In these cases, the RCD after a failed TOLAC is more likely to be complicated by maternal hemorrhage, operative injury, and infection. If a repeat CD is needed after attempting a TOLAC, the risks are actually higher than if a planned ERCD {prior to the onset of labor and without attempting a TOLAC} was done in the first place.

Uterine rupture most often occurs during labor {i.e. during a TOLAC} in a patient with a prior CD and is a complication that can significantly affect both patient AND baby. Uterine rupture occurs when the previous incision on the uterus opens up prior to or during the labor process; this is a true obstetrical emergency. Finally, the risk of a uterine rupture during labor in a patient with a prior CD is largely dependent on the type of incision made on the uterus during the prior CD. As a result, it is essential to know what type of incision was made on your uterus before considering a TOLAC. Requesting the operative report from your last CD is necessary so your current provider can determine with certainty what type of incision you had on your uterus and if it is compatible with attempting a TOLAC.

There are numerous ways that an incision can be made on the uterus, but the following are the most common:

  1. Low transverse—A side-to-side cut made across the lower, thinner part of the uterus. This is the most common type of incision and carries the least chance of future rupture.
  2. Low vertical—An up-and-down cut made in the lower, thinner part of the uterus. This type of incision carries a higher risk of rupture than a low transverse incision.
  3. High vertical (also called “classical”)—An up-and-down cut made in the upper part of the uterus. This is sometimes done for very preterm cesarean deliveries. It has the highest risk of rupture.
Uterine Incisions

In the appropriate candidate, the chance of having a complication from a TOLAC is essentially equal to that of an ERCD. However, it is recommended that certain factors be included in the decision-making process when determining if you are a good candidate for a TOLAC. Those who are successfully able to achieve a VBAC have less hemorrhage and infection and a more rapid recovery time than if they undergo an ERCD. In other words, a successful VBAC has less risk and complications than a planned ERCD.

Who is or is not a good candidate for a TOLAC?

Good candidates:

*most patients with one previous CD with a low-transverse incision  Conversely,

Not a good candidate:

*individuals at high risk of having a uterine rupture (eg, those with a previous classical or T-incision, prior uterine rupture, or extensive transfundal uterine surgery)

*those who have a contraindication to vaginal delivery

What can increase or decrease my chances of having a successful VBAC?

According to ACOG, most studies looking at patients attempting TOLAC have demonstrated a vaginal delivery rate of 60–80%.

Factors that can increase the likelihood of a VBAC include:

*having at least one prior successful vaginal delivery or VBAC

*entering spontaneous labor on your own

*the first CD was done for a nonrecurring indication, i.e. fetal breech presentation or twins or placenta previa

*spontaneous labor without augmentation

Factors that can decrease the likelihood of VBAC:

*having an induction or augmentation of labor with the TOLAC

*being of older age

*having a higher body mass index {BMI}

*the fetus is large {> 4000-4500 kg}

*the gestational age is beyond 40 weeks

*the first CD was done for a recurring indication, i.e. failure to dilate in labor or failure to push the baby out

*a shorter interdelivery interval (less than 19 months)

*the presence of preeclampsia at the time of delivery

In clinical practice, a “VBAC calculator” may be used to counsel patients who have one prior CD through a lower transverse uterine incision {i.e. the incision on the uterus goes side-to-side rather than up and down} and a current pregnancy with a singleton gestation. This calculator may give you a probability of success with an attempted TOLAC, which can help you decide whether or not you want to attempt a TOLAC. However, it should be known that no prediction model for VBAC has been shown to result in improved patient outcomes.

Whether or not to attempt a TOLAC is a very complex decision that involves an important conversation between the patient and provider. It is also a decision that may be influenced over time depending on how the pregnancy progresses and any complications that may arise. The best decision for the safety and health of both patient and baby is desired by all parties involved.


ACOG-Vaginal Birth After Cesarean Delivery (VBAC)

VBAC Guidelines: Who is a Candidate for a Trial of Labor after Cesarean Delivery?

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