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.

If I Was a Betting Woman...

Twelve days late, for the third time.  Same weight gain for momma; for the third time.  Birth weight identical to one sibling and 2 ounces less than the other.  If I was a betting woman, I would start placing bets on my pregnancies.  That is if there were going to be a fourth one.  I am (almost) positive this is the last baby for us.  I think. 

Little Miss has arrived.

Episiotomy or Not?

Episiotomy use in the United States has decreased dramatically in the last few decades.  In the year 2000, about 30% of women still underwent an episiotomy during delivery.  Currently the recommendation is that episiotomy should not exceed 5-8% of use during vaginal deliveries.

So what is an episiotomy?  Essentially it is a cut made is the delivering woman’s vaginal opening while she is pushing out the baby.  Historically, there were thought to be multiple benefits to this procedure.  Most, if not all, have not been supported by research.  In fact, woman who have an episiotomy tend to have more pain after delivery (and during the procedure!), further risk of tearing, and increased risk of pelvic floor dysfunction to name a few disadvantages to the procedure.

In 2006, yes 10 years ago, the American College of Obstetrics and Gynecology recommended against the routine use of episiotomies.  However, what we in the obstetric world know is this varies greatly by physician practice.  In fact, some research has found that private practitioners (as opposed to residents or hospital based physicians) have the highest rates of use.   

There are very few acceptable reasons for an episiotomy and even those aren’t always concrete.  I think most practitioners would agree that if a baby is in distress and the episiotomy will expedite the delivery, then yes an episiotomy is appropriate.  However, another reason often considered acceptable, is to prevent severe maternal perineal tearing.  This benefit would be difficult to prove.  How does the physician know how severely the woman will tear?  I haven’t heard or read a good prediction of tearing yet.

It is important to ask your practitioner what their episiotomy rate is.  They should know the answer to this question.  And if they claim they don’t, ask “50%? 33%? Less than 10%?”  Then I think the next question is, when would you do an episiotomy?  They should speak to expediting delivery when the baby is in trouble.  If you hear, “easier to repair, protect the pelvic floor, or every first time mom needs one” this should raise some red flags. 

Feel like you need more information about episiotomies? This is a summary of the ACOG recommendation.

Choices in Childbirth has more information about the procedure itself and how to potentially avoid the procedure.