Updated: Jun 23, 2019
The thing about statistics is, they will not tell you how a specific person, in a specific circumstance, will react under certain conditions. However, statistics and good solid info will help you make a decision relative to the associated risks. Uterine rupture does happen, and here, we discuss what the REAL risks are so YOU can make the best decisions for your birth.
Up to 80% of women who attempt a VBAC will be successful, and VBAC is generally associated with fewer complications than a repeat Cesarean. The biggest risk and the most influencing factor for VBAC is uterine rupture. A uterine rupture is defined as a tear through all three layers of the uterine lining. However, uterine rupture can even occur in women without a prior Cesarean, albeit not as likely (0.07%), or one in 1,146 pregnancies.
Uterine Rupture vs. Uterine Window and Dehiscence
Uterine rupture is rare, although it does happen; uterine dehiscence is often mistaken and classified as a uterine rupture. Uterine rupture is when the uterine scar completely opens along the scar going through every single layer of the tissue. A dehiscence is when a very small amount of the scar begins to separate but doesn’t quite make it the entire distance. A uterine window is when the scar is so thin that you can see through it but it does not tear or open. After a Cesarean, our bodies heal and create scar tissue. That scar tissue is not as stretchy as our original tissue, but it still has the ability to stretch.
As your baby grows, the uterus stretches and can become thin. In order to know if you have a uterine window, a Cesarean would need to be performed or an ultrasound may show the thinning. Your provider would be able to tell you during the Cesarean because of how thin it would look. Evidence has not shown thus far if a uterine window is an indication that a rupture would be more likely or not. A lot of parents will likely go on and VBAC without knowing if their uterine lining ever was thin.
There are three layers to the uterus. If the uterine scar opens partially, stretching the scar tissue and opening the bottom layer, this would be classified as a uterine dehiscence. Uterine dehiscence is often harmless and doesn’t have any harmful effects on the baby or the mother. A 10-year Canadian study was done on full uterine rupture vs. uterine dehiscence. Over the 10 years, there were 114,933 deliveries with 39 cases of uterine rupture: 18 complete and 21 incomplete, or dehiscence. Uterine dehiscence did not have any fetal deaths. Uterine rupture is a scary topic for providers. It can often be hard for women to be able to find a supportive provider for VBAC due to this fear.
How to Determine Uterine Dehiscence
As with the uterine window, a repeat Cesarean would need to be performed in order to confirm uterine dehiscence. Historically, providers would explore the uterus more during a Cesarean to see if there were any other tears, but currently that practice is not likely to happen. Taking the mother’s pulse rate carefully and consistently during labor may be the only sign that uterine dehiscence is happening or has happened. When the scar tissue starts to separate, fluid can enter the body cavity and leak into the membrane that separates the organs from the cavity wall. When this happens, the body reacts with shock and the mother’s heart rate may increase dramatically. In the same 10-year study, in 92% of cases, uterine rupture was associated with previous Cesarean delivery (Kieser & Baskett, 2002). Uterine dehiscence was associated with minimal maternal and perinatal morbidity.
Putting Uterine Rupture into Perspective
Statistically, uterine rupture happens in 0.4% of TOLAC. That equals one in 240. Now, as will all things, probability should be considered and assessed. When uterine rupture does happen, most of the time it is quickly detected and a provider is able to get the baby out quickly (usually by repeat Cesarean) before any long-term damage happens to the mom and/or baby. In fact, only 6% of uterine ruptures are complete or catastrophic.
“The overall risk of perinatal death due to uterine rupture was 6.2 percent. The two studies of women delivering at term that reported perinatal death rates report that 0-2.8 percent of all uterine ruptures resulted in a perinatal death.” (Guise, et al., 2010)
To put it differently, of the women who had a uterine rupture, one in 16 resulted in infant death. When looking at the overall chances of infant death when attempting a VBAC, the National Institute of Health (NIH) reports the odds as 0.13%, which ends up being one infant death in every 769 TOLACs. For comparison, the average neonatal mortality rate for the U.S. in 2014 was 5.8 per 1,000 births. That’s one in approximately 172. Just for fun, and because I am a statistics geek, let’s take a look at some things more likely and a little bit less likely to happen to you than a uterine rupture:
1 in 160 - Chance of having a heart attack each year (CDC, NCHS, 2015).
1 in 216 - Chances the person you are dating is a millionaire (Baer, 2003, Life: The Odds).
1 in 4 - Chances of your death being due to heart disease (CDC, NCHS, 2015).
1 every 18 years - How frequently you will be in a car accident (Property Casualty Insurers Association of America, 2018).
1 in 30 - Odds of conceiving twins (Martin, Hamilton, Osterman, Driscoll, & Drake, 2018).
1 in 300 - The risk of cord prolapse (Lore, 2018).
1 in 160 - Odds of being audited by the IRS (Heath, 2018).
1 in 199 - Odds of falling to your death (McCarthy, 2018).
1 in 14 - Odds of having your identity stolen if you are 16 years or older (Matko, 2013).
1 in 100 - Odds of dying from an obesity-related conditions (Allison, Fontaine, Manson, & Stevens, 1999).
1 in 38 - Chance of developing melanoma (American Cancer Society, 2018).
Reducing the Risk of Uterine Rupture
There are many things you can do to minimize the chances of uterine rupture. It is important to discuss these things with your provider and have a solid plan ready if any interventions are necessary.
Stay away from induction unless absolutely necessary.
Avoid augmentation of labor (something to stimulate contractions, usually Pitocin).
Avoid excessive Pitocin and upping the dose too fast.
Avoid Cytotec (misoprostol) COMPLETELY.
Avoid providers who aggressively intervene with and manage labor.
Stay mobile. Walk, change position and posture when in active labor.
In early labor and if labor stalls, rest or sleep.
Do EVERYTHING you can to make sure your baby is in the most optimal position BEFORE labor begins.
If baby is not in a great position and labor stalls or you have back labor: try spinning babies, MILES circuit, abdominal lifting, side lying, or get on hands and knees to try and help baby settle into a better position.
Avoid rupturing membranes if baby is not in optimal position.
Avoid an epidural if possible.
Have attentive labor support with you ALL THE TIME.
Be aware of typical labor patterns. Any stalls in labor are usually indicative that something needs to change (emotional processing, baby position, rest/sleep, and even Pitocin in some instances). Figure out what needs to change and fix it if you can. A long stall combined with high doses of Pitocin is a prime scenario for uterine rupture.
HONOR YOUR INTUITION. If you feel that something is not quite right or if baby’s movement is significantly decreased, insist that your provider or their staff attention to you. In many instances, uterine rupture occurs when a mother knows something is wrong intuitively before providers pay sufficient attention.
Listen to our friend Heather on episode 56 of the podcast to hear her experience with a uterine rupture.
Need some VBAC inspiration? Download our VBAC affirmations created just for YOU right here.