A vaginal birth after a previous delivery via cesarean section (C-section) is called a VBAC delivery. For a long time, doctors believed that if you had delivered a baby via C-section, all subsequent babies needed to be delivered via C-section as well for the safety of mom and baby. C-section delivery rates increased from 5 percent in 1970 to a high of 31.9 percent in 2016 in great part due to repeat C-section deliveries. We now know that a VBAC delivery is safe and possible for many women, but there are numerous factors that need to be taken into consideration when determining whether a VBAC delivery might be right for you. If you’ve had a previous C-section with a low transverse incision and are pregnant or planning to become pregnant, starting the conversation with your providers early can be helpful.
PRCD and TOLAC
If you have had a previous C-section delivery, there are two options to consider for a subsequent delivery: a planned repeat cesarean delivery (PRCD) or a VBAC delivery through trial of labor after cesarean (TOLAC). VBAC delivery is often successful: In 2013, 70 percent of women who attempted TOLAC after one prior C-section accomplished a VBAC delivery.
There are risks and benefits to each option, but the biggest concern with a VBAC delivery is the risk for uterine rupture. This risk is quite small (happening in less than 1 percent of women who attempt a TOLAC), but because a uterine rupture can be life-threatening for both mom and baby, it is generally recommended that TOLAC and VBAC deliveries are only planned at facilities that have the capability to perform emergency C-sections, and a VBAC delivery is generally considered too risky for a home birth.
There are risks and benefits to each option, but the biggest concern with a VBAC delivery is the risk for uterine rupture.
In terms of overall risk of complications, VBAC deliveries result in fewer complications than PRCD deliveries; however, there are more complications associated with C-section deliveries after TOLAC than with either PRCD or VBAC deliveries. Providers have different calculators and algorithms they can use to help determine whether a PRCD or VBAC delivery is the best choice, but it’s good to keep in mind that things can change as the pregnancy progresses. For example, if you decide on a VBAC delivery but develop a complication (such as preeclampsia or placenta accreta), your plans might need to change.
Who shouldn’t have a VBAC delivery?
While you and your providers can decide whether you are a good candidate for a VBAC delivery based on your personal health, labor and delivery history, and specific details of your current pregnancy, there are some individuals for whom a VBAC delivery is unlikely to be a safe option.
Generally, you are not a good candidate for a VBAC delivery if you:
· Have a condition that would prevent a vaginal delivery (e.g., placenta previa)
· Have had more than two previous C-section deliveries
· Have had a prior high vertical (also called classical), T, or J uterine incision
· Have had an unknown type of previous uterine incision, but it’s suspected to have been a high vertical/classical type
· Have had a previous uterine rupture
· Have had certain prior uterine surgery that might make you high risk for uterine rupture
· Are pregnant with three or more babies
· Have a body mass index (BMI) over 50 at the time of delivery, and you’ve never had a vaginal delivery
Some of these are non-negotiable (for example, if you’ve had a previous uterine rupture or high vertical uterine incision), but others may be provider-dependent (like in a situation where you’ve had more than two low transverse C-section deliveries).
Factors affecting a VBAC delivery
Certain factors can affect the likelihood of a successful VBAC delivery, and one of the biggest predictors for a successful VBAC delivery is a prior vaginal delivery. Having a successful vaginal delivery (either before or after a prior C-section) triples the success rate of a VBAC delivery and also lowers the risk of uterine rupture.
Factors that decrease the likelihood of a successful VBAC delivery can include advanced maternal age, gestation past 40 weeks, labor that does not progress, lower Bishop score (which looks at your body’s preparedness for labor and delivery), obesity or excessive weight gain during pregnancy, previous delivery within the past 18 months, preeclampsia and other hypertensive disorders of pregnancy, diabetes (both pre-pregnancy and gestational diabetes that develops during pregnancy), and a history of two or more prior C-sections and no vaginal deliveries. No single one of these factors means you automatically won’t have a successful VBAC delivery, but it is important information for you and your providers to take into account when making decisions about whether to choose a repeat C-section or aim for a VBAC delivery.
One of the biggest predictors for a successful VBAC delivery is a prior vaginal delivery.
The reason(s) for your previous C-section(s) is also a factor to consider. If your previous C-section was the result of baby’s positioning (e.g., baby was breech or transverse), you have a greater likelihood of a successful VBAC delivery than if the C-section delivery was due to factors such as a failed labor induction, failure to progress, cephalopelvic disproportion (when baby’s head is too big to fit through mom’s pelvis), or macrosomia (larger-than-average baby).
What are the benefits of a VBAC delivery?
If you have had one or two low transverse C-sections and aren’t experiencing any pregnancy complications that would preclude a vaginal delivery, a VBAC delivery might be an option to consider. There are many reasons why a pregnant woman might elect to try TOLAC for a VBAC delivery:
· Faster recovery time (typically, it is easier to recover from a VBAC delivery than a C-section)
· Planning for future pregnancies (multiple C-sections can put you at higher risk of placental complications like placenta previa and placenta accreta in future pregnancies)
· Lower risk of surgical complications like infection, bleeding, blood clots, etc.
· Wanting to experience a vaginal delivery
Choosing a VBAC delivery (or PRCD if that’s what’s best for you and your personal situation) is a decision you can make with the knowledge and support of your provider. As with any labor and delivery plans, flexibility is key. It’s best to start the conversation early, and make sure your provider has your complete medical history so they can assist you in making the most informed choice possible.