The Reason For Your Primary C-Section Impacts The Likelihood Of A VBAC
C-section delivery rates in the United States increased from 5% to 25% from 1970-1988.
Current day cesarean rates in the United States are 31% nationally and over 34% in Texas, our home state. The reason for this? According to the above article in American Family Physicians, three factors contributing to this massive increase include: increased pressure to not perform vaginal breech delivery, pressure to not perform mid-pelvic forceps deliveries and increasing reliance on continuous electronic monitoring of fetal heart rate and contractions.
A 2015 article in the British Journal of Obstetrics and Gynecology, the c-section rate associated with a reduction in maternal and neonatal mortality is 10%. Needless to say, the US has exceeded that.
Now up until the 1980s it was believed that once someone has a c-section, they’ll always have a c-section. Beginning in the 80s, specifically between 1985 and 1995, folks were encouraged to attempt a vaginal birth after cesarean (VBAC) and VBAC rates increased by 20%, up to 28% in 1998 with a national reduction in c-sections. Despite a 75% success rate of VBACs, as the medical system became aware of potential complications (read: uterine rupture), malpractice insurance went up and VBACs went down to their current rate of roughly 13%.
Now, uterine rupture is not a complication to make light of. Uterine rupture is an emergency situation that most often occurs during labor. The incidence of uterine rupture is between 1 in every 5700 to 20,000 pregnancies, or .017-.005% of VBACs. While this is a serious complication, it’s necessary to keep perspective of the likelihood of this complications when assessing the safety of a VBAC attempt.
Ok, now that we’re on the same page. Let’s move on.
Common causes of c-sections
Let’s dig in to the common causes of c-sections, broken down into planned and unplanned c-sections. For clarity, planned c-sections are c-sections planned for before the birthing person arrives to the hospital. These are the people that show up and know they’re having a c-section. Unplanned cesareans are unexpected c-sections and include emergency c-sections. The causes of planned vs unplanned c-sections overlap but vary.
Planned c-sections commonly occur for the following reasons:
Placenta previa: This is when the placenta either partially or completely covers the cervix.
Fetal positioning: While babies can be delivered breech, many providers will opt for a c-section in the case of a breech baby.
Higher order multiples: Folks carrying twins may opt for a vaginal birth, triplets and above are an indication for c-section.
Active maternal herpes or HIV+ with a high viral load at the time: A c-section is recommended to reduce the likelihood of transfer to the baby.
Previous uterine surgery: This is a yellow flag and depends on the surgery and scar positioning. Someone who has a vertical scar on their uterus will be recommended to have a c-section, while a low transverse scar doesn’t rule out a future vaginal birth.
Pulmonary or coronary disease of the birthing parent, or severe preeclampsia: This is to protect the health of the birthing person and baby.
Cephalopelvic Disproportion (CPD): While over diagnosed, there are cases of CPD that indicate the need for a c-section.
Unplanned c-sections commonly occur for the follow reasons:
Failure to progress: When labor is slowed or delayed. This is a somewhat subjective term with varying presentation.
Fetal distress: When your practitioner is concerned about the baby’s health.
Cord prolapse: When the cord exits the cervix before the baby.
Placental abruption: When the placenta separates from the wall of the uterus before the birth of the baby.
Uterine rupture: Spontaneous tearing of the uterus.
Repeatable vs non-repeatable causes
The reasons above were broken into planned vs unplanned cesareans. These reasons can be further broken down into repeatable vs non-repeatable causes. Repeatable causes are causes that limit the likelihood of a future VBAC. Non-repeatable causes are less likely to impact the likelihood of a future VBAC.
Non-repeatable factors (factors less likely to impact a future VBAC) include:
fetal positioning
fetal distress
Repeatable factors (factors that increase the likelihood of a repeat c-section) include:
vertical incision from previous c-section
labor dystocia (failure to progress, dilate)
multiple c-sections
underlying medical conditions
A prospective observational study from 2013 found that out of 100 participants, 85% of those who attempted had a VBAC and 15% underwent a repeat c-section. They found that those who arrived dilated >3cm had a better chance of vaginal delivery (90%), while those who arrived with cervical dilation <3cm had a 60% chance of a vaginal birth. VBAC rates for those with nonrecurrent indications (fetal distress, malpresentation, pre-eclampsia, premature rupture of membranes) was 80-90%. Those who had a primary c-section due to failure to progress or CPD had a 60-70% success rate.
It’s important to call out that VBAC rates were still reasonably high (60-70%) in folks with repeatable factors as primary c-section causes.
If you’re interested in pursuing a VBAC
Before you get caught up in all the information shared above, it’s important to remember that every body is different. Pregnancy and birth are highly personal experiences. If you’re interested in pursuing a VBAC, I recommend starting with an informed conversation with your medical provider.
Find a provider who truly supports VBACs (check out this list by ICAN to ask your provider)
To learn more, listen to our webinar Understanding VBACs to Improve Outcomes
If you have the resources, hire a Doula
Work with a pelvic floor PT during pregnancy to manage addressable factors
Want to learn more about c-section scar pain and recovery?
Click here to learn about our self-paced, c-section recovery program to help you reduce pain and sensitivity around your scar while regaining strength and confidence after your cesarean. It’s never too late or too early to start supporting your body through your recovery.
To learn more about how pelvic floor physical therapy can help you prepare for a vaginal birth after cesarean, contact us here!
This post was written by Dr. Rebecca Maidansky, PT, DPT, owner and founder of Lady Bird Physical Therapy. Rebecca is a pelvic floor physical therapist in Austin, TX and founded Lady Bird Physical Therapy in 2019. She is the creator of Birth Preparation and Postpartum Planning, Baby Steps Fitness and the head writer and editor of The Pelvic Press.
Rebecca is a passionate writer and vocal advocate for pelvic health and the importance of improving access to perinatal care. She believes strongly that many common pregnancy pains and postpartum symptoms can be eased or even prevented with basic education and care.
She created this blog to help all birthing people manage common pregnancy pains, prepare for birth and recover postpartum.