How Can I Increase My Chances of a VBAC?

You might be asking yourself, what can I do to increase my chances of a vaginal birth after cesarean (VBAC)? Here are a few newer studies I read and some thoughts about them.  (Please know, while I try to look at high quality studies, I am not a nurse researcher and this is in no way an extensive literature review.)

Two things to consider, birth location likely matters, and maternal/fetal weight gain impacts outcomes as well.  I think it is great the literature is reflecting birth location and outcome.  This is true for vaginal birth and cesarean in general, not just VBAC.  When possible, try to find information on birth settings in your area.  Pre-pregancy weight and pregnancy weight gain are not new.  This is something to pay attention to when planning for a VBAC.  I would say this is probably more important if you are planning a hospital birth rather than birth center/home birth.  Typical US hospital practices lead to immobility during labor. 

Hospital contribution to variation in rates of vaginal birth after cesarean  https://www.nature.com/articles/s41372-019-0373-2

In the most basic language – hospital matters.  Vaginal birth after cesarean section rates among Michigan hospitals varied greatly.  This is well known in New York as statistics are publicly reported.  In this link you can see which NYS hospitals have the highest VBAC rate by first selecting vaginal births and then vaginal birth after cesareans.  If you have a choice between hospitals you might want to make it based on this information like this.   

Practice variation of vaginal birth after cesarean and the influence of risk factors at patient level: a retrospective cohort study https://obgyn.onlinelibrary.wiley.com/doi/epdf/10.1111/aogs.13059

While not a USA based study, this one also points to hospital variation in rates. 

Factors associated with successful vaginal birth after a cesarean section: a systematic review and meta-analysis https://bmcpregnancychildbirth.biomedcentral.com/articles/10.1186/s12884-019-2517-y

This review included 94 studies, so there is a lot of information in it!  It is open access, so feel free to read through more thoroughly.  I will just highlight a few aspects that are potentially modifiable. 

Obesity & Fetal Macrosomia are more likely to result in an unsuccessful VBAC attempt.  If possible, maintain or obtain a healthy BMI prior to pregnancy.  During pregnancy pay attention to recommended weight gain. 

Gestational diabetes was also more likely to result in an unsuccessful VBAC. 

Avoid induction of labor if not medically necessary.  Gestational age did not impact outcome.  This is a good reminder to not fall into the belief that if labor doesn’t happen by XX (insert arbitrary number) gestational age, it isn’t going to happen.  Or that there needs to be a cut off of gestational age to be induced for a VBAC.  

 Vaginal birth after a cesarean delivery for arrest of descent https://www.tandfonline.com/doi/abs/10.1080/14767058.2018.1443069

Note - this study is small.  100 women attempted VBAC after a cesarean for arrest of descent (pushed, but baby wouldn’t descend), 84 delivered subsequently delivered vaginally!  In general 84% is considered a high success rate, but particularly after an arrest disorder, this is pretty incredible.  The authors conclusion was: This suggests that arrest of descent is mostly dependent on factors unique to each pregnancy and not due to an inadequate pelvis or recurring conditions. Women with a prior CD for arrest of descent should not be discouraged from attempting TOLAC in a subsequent pregnancy due to concerns about the likelihood of success.

I hope you are continually encouraged that the majority of women are candidates for VBAC! Access and support for VBAC are critical and in my opinion the biggest predictor of success.

VBAC Series: What Else Does ACOG Have to Say?

www.freeimages.com/ Nic O' Reilly

Despite the negative effects of the ACOG practice bulletin on vaginal birth after cesarean, the document does contain many positive points that are often ignored by obstetric care providers.  I encourage you to read the document if you are pursuing or deciding if you want to pursue a VBAC. 

Here are a few highlights:

1.     It is reasonable to attempt a trial of labor after cesarean if you have had two low transverse cesarean sections.  This is also true if the woman does not know what type of scar she has. 

2.     While macrosomia may increase the risk of uterine rupture, this alone should not solely make the decision of repeat cesarean.

3.     Going past her due date may decrease the likelihood of successful vaginal delivery, but this does not mean she should not attempt a TOLAC.

4.     Twins have similar success rate of VBAC as singletons.

5.     It is reasonable to induce or augment a TOLACs labor, but care should be taken in doing so.

6.     External cephalic version (attempt to turn a breech baby vertex) can be considered to avoid repeat cesarean. 

7.     Women can chose epidural analgesia as in any labor.

If you are finding your provider is putting multiple stipulations of on your pursuit of a VBAC (delivery by due date, only if baby isn’t thought to be too large, etc) you may want to compare their care to this practice bulletin.  In the end, you want a provider who believes VBAC is a good thing, rather than someone who will just “allow” it to happen under their strict criteria. 

VBAC Series: What Does ACOG Have to Say?

The American College of Obstetrics and Gynecology (ACOG) issued a practice bulletin in 1999 about Vaginal Birth After Cesarean.  Within this practice bulletin, providers were encouraged to counsel women regarding VBAC and the likelihood of their success, but that delivery should only occur in a setting where immediate emergency care can be offered.  While the first part of the recommendation is based on good scientific evidence, the second part of the recommendation is based solely on consensus and expert opinion. 

In 2010 a new practice bulletin was created, and this was reaffirmed in 2015.  The 2015 version starts by mentioning the large decrease in the number of women attempting a Trial of Labor after Cesarean (TOLAC).  In 1996 the number of VBACs reached 28.3% (that is the percent of women delivering vaginally after a prior cesarean), and now most sources put the VBAC rate around 10% nationally. 

Why the shift?  The ACOG bulletin states the increasing fear of uterine rupture and liability has led to the sharp decline.  However, they fail to mention their own statement about access to emergency care as part of the decline.  While there was a slow decline from 1996-1999, the decline steepened after the release of the 1999 practice bulletin.

In a 2007 paper in Birth journal, researchers called over 200 hospitals in their region, and found 30% had stopped offering VBACs based on the 1999 ACOG practice bulletin.  As a result access to VBAC has become far more limited in this area, and one could imagine this is also the case nationally. 

This report appears to have a great deal of information about VBAC and its safety, but I admit at 300+ pages, I have only begun to skim through it.  It also makes mention of this paper starting the decline of VBACs (check out the graph on page 12 of the report) in addition to the ACOG practice bulletin. 

The ACOG practice bulletin has MANY good points about VBAC and how the majority of women are good candidates for a trial of labor.  What is unfortunate, though, is how a single statement based on consensus and expert opinion, rather than scientific evidence, has done so much to shape access to a TOLAC. 

VBAC Series: Vaginal Birth After Cesarean (VBAC) Resources

On a personal note, I had a cesarean section with my first child.  Two and a half years later I had a vaginal birth after cesarean, commonly shortened to VBAC.  During that time I searched the Internet tirelessly looking for resources, stories, anything that would lead me to remain hopeful or perhaps increase my chances of success. 

While there were a few solid resources, I wanted more!  My hunger for information could not be satisfied.  Now two years later, I was curious to see what was still out there and if there was anything new.

Here is my round up:

www.vbac.com

This website has become a wealth of knowledge.  I haven’t even scratched the surface of her new resources.  As far as I can tell, it all looks free.  I look forward to reviewing her new The VBAC Education Project. 

www.vbacfacts.com

I was hoping this website would be a little easier to navigate after a few years, but while it has been updated, I am not in love with the format.  There still seems to be a great deal of information on the website, just a little buried.   Jen Kamel (the creator) has workshops around the country, and they look well worth cost/time. 

American College of Obstetrics and Gynecology (ACOG)

ACOG has practice bulletins, which should guide obstetricians practicing in the United States.  They are in support of VBAC, and their guidelines are far less restrictive than how most obstetricians practice. 

NIH Consensus

Another position paper in support of VBAC

Childbirth Connection

Overall, this is a solid website that focuses on evidence based care.  There is a good deal of information about VBAC and repeat cesarean.  While I do think the information is good, I want to point out that the last time this section was updated was 2012. 

International Cesarean Awareness Network

A website dedicated to providing resources to women who have had a prior cesarean.  They also have local chapters where women who have had a cesarean can meet together. 

www.trialoflabor.com

This is a documentary that explores a women’s journey to VBAC.  Definitely worth the watch.

Ina May's Guide to Childbirth

This book is not specific to VBAC, but there are a few stories about VBAC in it.  The most important part of this book is the normalization of childbirth.  Ina May Gaskin is an amazing birth advocate, this is a must read.

 The Official Lamaze Guide: Giving Birth with Confidence

Another good read that normalizes birth.

Many websites have a page or two dedicated to VBAC, but these resources dig deeper, fully aware that knowledge is power when pursuing or deciding about a VBAC. Is there anything I missed, a resource you found particularly valuable to your journey?