The Alphabet Soup of Vaginal Birth After Cesarean {VBAC} Delivery

Shannon M. Clark, MD
March 1, 2020
The Alphabet Soup of Vaginal Birth After Cesarean {VBAC} Delivery

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

Putting the letters together!

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 Cesarean delivery.

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

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 woman who has had a prior CD and desires to electively undergo a RCD prior to the onset of labor.

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. 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?

A ‘TOLAC’ is the process of attempting to have a vaginal delivery after having had a CD. Once a woman has successfully had a vaginal delivery after a prior CD, she has had a ‘VBAC’.

Do all providers offer their patients VBACs?

Because of the significant complications that can occur {see below}, 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 woman 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 woman undergoing a TOLAC, should be present at all times in the hospital while managing the patient. Finally, TOLAC should occur in hospitals equipped to perform an emergent Cesarean delivery. This means that not only does the provider need to be available in the hospital at all times to perform an emergent Cesarean delivery if necessary, but anesthesia providers should also be present and available in the hospital to provide anesthesia for labor during the TOLAC and a CD if needed. Not all hospitals require that the obstetrical care or anesthesia provider 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 he/she does 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 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 due to failed 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 woman with a prior CD and is a complication that can significantly affect both mom 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 woman 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 is ideal.

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. Women 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 than a planned ERCD.

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

Women who have had at least one prior successful vaginal delivery or VBAC, or those who enter spontaneous labor on their own have a greater probability of achieving a VBAC. In addition, if the first CD was done for a nonrecurring indication, i.e. fetal breech presentation, there is a greater chance for VBAC success. In contrast, there is a lesser chance of success if a woman has an induction of labor with her TOLAC, she is of older age, she has a higher body mass index {BMI}, the fetus is large {> 4000-4500 kg}, or the gestational age is beyond 40 weeks. In addition, if the first CD was done for a recurring indication, i.e. failure to dilate in labor or failure to push the baby out, there is a lesser chance of success.

In clinical practice, we use a “VBAC calculator” to counsel women who have one prior Cesarean delivery 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 allows us to give you a probability of success with an attempted TOLAC, which can help you decide whether or not you want to attempt a TOLAC.

The calculator takes into account factors that we know contribute to the chance of VBAC success and failure. Some of these factors include maternal age, height, and weight; whether or not you had a successful vaginal delivery in the past; whether or not you had a successful VBAC in the past; and whether the reason of the first Cesarean delivery was for a recurrent indication {as mentioned above}. It is commonly accepted that if the calculator shows that you have a 60-70% or more chance of having a successful TOLAC, you have the same risks while attempting a TOLAC as a woman undergoing an ERCD.  If the chance of success is <60%, your risk of a complication is greater with a TOLAC than with an ERCD.

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 mom and baby is desired by all parties involved.

This article first appeared in Houston Moms Blog. Click here to check out the site!

Shannon M. Clark, MD

Shannon M. Clark, MD

Shannon M. Clark, MD, MMS is a double board certified ObGyn and Maternal-Fetal Medicine Specialist, and founder of Babies After 35. In her roles as a clinician, educator and researcher at UTMB-Galveston, she focuses on the care of people with maternal and/or fetal complications of pregnancy. Dr. Clark has taken a special interest in pregnancy after the age of 35, which according to age alone, is considered a high-risk pregnancy.

Follow Shannon on TikTok @tiktokbabydoc, Facebook @babiesafter35, and Instagram @babiesafter35.

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