Thoughts on VBA3+C (VBAC after three or more prior cesareans)

Note regarding “TOLAC.”  When reading from medical texts, remember that you are no longer in the land of emotion and warm fuzzies.  Rather, envision that you have been transported to another world, a clinical world, where terms like TOLAC/TOLAMC, or trial of labor after (multiple) cesareans, are used.  I don’t think that most care providers understand the emotional sting that many women seeking VBAC associate with the term TOLAC.  It’s important for women to understand the language care providers use so that they can translate TOLAC into “planning a VBAC” and not feel slighted.  You might want to read this article which describes what the term TOLAC means, how it’s used in medical research, and why it’s not synonymous with VBAC.

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A mom recently asked over on the VBAC Facts Community, “Does anyone have some facts on vab3c?”

I provided this mish-mash of info…

Who makes a good VBAC/VBAMC candidate?

ACOG’s 2010 VBAC recommendations affirm that VBA2C (vaginal birth after two cesareans) is reasonable in “some” women.  Between what they say about VBA2C and who is a good VBAC candidate, we might be able to discern who might be a good VBA3+C (vaginal birth after three or more cesareans) candidate. (For a really great, though growing outdated, review of the VBAMC research click here.)

A couple things to keep in mind while reading…

Reason for prior cesarean/history of vaginal birth.  Like women with one prior cesarean, I would suspect that women who have had cesareans for malpresentation (breech, transverse lie, etc) and/or a history of a prior vaginal delivery would have the highest success VBAMC (vaginal birth after multiple cesarean) rates.  In women with one prior cesarean, the average success rate is about 75%.  This increases to over 80% among women who had their cesarean for malpresentation and/or a history of a prior vaginal delivery.

Scar type.  Low transverse incisions (also called bikini cuts) carry the lowest risk of rupture in comparison to classical, high vertical and T/J incisions.  With the likely increased risk of uterine rupture in a VBAMC (we don’t have a lot of great data for VBA2C and even less so for VBA3+C), I think having low transverse incisions would be ideal.

Here ACOG describes the qualities of a good VBAC candidate:

Good candidates for planned TOLAC are those women in whom the balance of risks (low as possible) and chances of success (as high as possible) are acceptable to the patient and health care provider. The balance of risks and benefits appropriate for one patient may seem unacceptable for another. Because delivery decisions made during the first pregnancy after a cesarean delivery will likely affect plans in future pregnancies, decisions regarding TOLAC should ideally consider the possibility of future pregnancies.

Although there is no universally agreed on discriminatory point, evidence suggests that women with at least a 60–70% chance of VBAC have equal or less maternal morbidity when they undergo TOLAC than women undergoing elective repeat cesarean delivery (62, 63).  Conversely, women who have a lower than 60% probability of VBAC have a greater chance of morbidity than woman undergoing repeat cesarean delivery. Similarly, because neonatal morbidity is higher in the setting of a failed TOLAC than in VBAC, women with higher chances of achieving VBAC have lower risks of neonatal morbidity.  One study demonstrated that composite neonatal morbidity is similar between TOLAC and elective repeat cesarean delivery for the women with the greatest probability of achieving VBAC (63).

The preponderance of evidence suggests that most women with one previous cesarean delivery with a low transverse incision are candidates for and should be counseled about VBAC and offered TOLAC.  Conversely, those at high risk for complications (eg, those with previous classical or T-incision, prior uterine rupture, or extensive transfundal uterine surgery) and those in whom vaginal delivery is otherwise contraindicated are not generally candidates for planned TOLAC.  Individual circumstances must be considered in all cases, and if, for example, a patient who may not otherwise be a candidate for TOLAC presents in advanced labor, the patient and her health care providers may judge it best to proceed with TOLAC.

What does ACOG say about VBA2C?

In its latest VBAC recommendations, ACOG specifically addresses VBA2C:

Studies addressing the risks and benefits of TOLAC in women with more than one cesarean delivery have reported a risk of uterine rupture between 0.9% and 3.7%, but have not reached consistent conclusions regarding how this risk compares with women with only one prior uterine incision (64–68).  Two large studies, with sufficient size to control for confounding variables, reported on the risks for women with two previous cesarean deliveries undergoing TOLAC (66, 67).  One study found no increased risk of uterine rupture (0.9% versus 0.7%) in women with one versus multiple prior cesarean deliveries (66), whereas the other noted a risk of uterine rupture that increased from 0.9% to 1.8% in women with one versus two prior cesarean deliveries (67).  Both studies reported some increased risk in morbidity among women with more than one prior cesarean delivery, although the absolute magnitude of the difference in these risks was relatively small (eg, 2.1% versus 3.2% composite major morbidity in one study) (67).

Additionally, the chance of achieving VBAC appears to be similar for women with one or more than one cesarean delivery.  Given the overall data, it is reasonable to consider women with two previous low transverse cesarean deliveries to be candidates for TOLAC, and to counsel them based on the combination of other factors that affect their probability of achieving a successful VBAC.  Data regarding the risk for women undergoing TOLAC with more than two previous cesarean deliveries are limited (69).

The power of context and training

This hour long panel discussion followed the screening of More Business of Being Born: The VBAC Dilemma. On the panel are author/midwife Jenny West (The Complete Idiot’s Guide to Natural Childbirth and The Natural Healing Power of the Placenta), author/researcher Henci Goer (The Thinking Woman’s Guide to a Better Birth and Optimal Care in Childbirth), Nekole Shapiro of Embodied Birth, Stephanie Dawn of Sacred Birth and OB/GYN Dr. Craig Klose discussing the merits of vaginal birth after cesarean and various factors that may impede women being able to obtain VBACs.

One thing that stood out to me was Dr. Klose’s comments on VBAC after multiple prior low transverse cesareans (TLC). To sum, he says that he was taught that multiple LTCs were no biggie and he has attended up to VBA5C. This is the power of training and context!

ACOG guidelines, your legal rights, and “forced” cesareans

As attorney Lisa Pratt asserts, “ACOG guidelines are just that, guidelines, they are not law; while it is nice when they put out a guideline that supports your factual situation, falling outside of their recommendation does not mean you must consent to something you do not want.”  You can read in the article, “VBAC bans, excercising your rights, and when to contact an attorney.”

Further, ACOG also says that women cannot be forced to have cesareans even if there is a VBAC ban in place:

Respect for patient autonomy also argues that even if a center does not offer TOLAC, such a policy cannot be used to force women to have cesarean delivery or to deny care to women in labor who decline to have a repeat cesarean delivery.  When conflicts arise between patient wishes and health care provider or facility policy or both, careful explanation and, if appropriate, transfer of care to facilities supporting TOLAC should be used rather than coercion.  Because relocation after the onset of labor is generally not appropriate in patients with a prior uterine scar, who are thereby at risk for uterine rupture, transfer of care to facilitate TOLAC, as noted previously, is best effected during the course of antenatal care.  This timing places a responsibility on patients and health care providers to begin relevant conversations early in the course of prenatal care.

Read a summary of ACOG’s VBAC recommendations and the actual original document.  You may also wish to review your options when encountering a VBAC ban and the story of a mom seeking VBA2C who was threatened with a “forced” cesarean when her OB group withdrew support at 38 weeks.

Accreta, previa, hysterectomies, and cesareans

It has been well documented that the risks of placental abnormalities such as placenta accreta, placenta previa, and previa with accreta increase with each cesarean surgery and as a result, so does the rate of hysterectomy.  Silver (2006), a study of over 30,000 women and up to six cesareans quantified these risks per cesarean number.   You can read more about accreta, previa, previa with accreta and their associated complications.

Fang (2006) said, “abnormal adherent placentation [is] the primary indication leading to emergent peripartum [during the last month of pregnancy] hysterectomy… As the number of prior cesareans deliveries rises, the risk of cesarean hysterectomy increases dramatically.”

The Guise 2010 Evidence Report, which was the basis of the 2010 National Institutes of Health VBAC Conference, also discusses the risks of placental abnormalities by the number of prior cesareans.

So if you plan on having more children, a VBAMC (vaginal birth after multiple cesareans) would put a stop to the increasing rates of complications for future births as opposed to another cesarean which would just increase the risks in subsequent pregnancies.

Ultrasound/MRI and previa/accreta

Considering the significantly increasing risk of placenta previa and accreta as the number of prior cesareans increase, the fact that accreta as a 7% maternal mortality rate (due to hemorrhage) and a very high hysterectomy rate (one study found 71%), I do think it’s reasonable, especially if planning an out-of-hospital VBAMC, to have a ultrasound to rule out previa and even an MRI to try to rule out accreta.  (Keep in mind that the 7% & 71% statistics are based on hospital births where women have access to blood products, surgeons, and operating rooms and that if a mom has previa, the likelihood she has accreta rises dramatically.)

While MRI is more accurate for ruling out accreta than ultrasound, though there is no 100% accurate method thus far.

Read more on diagnosing accreta via ultrasounds versus MRI here.  You can also check out ACOG’s committee opinion on diagnostic imaging during pregnancy though accreta and previa are mentioned in passing.

What difference does it make if you know you have accreta before delivery?

Hospitals plan very differently for a delivery when accreta has been diagnosed.  Please go here for more detailed info.

Evidence to suggest previa less likely to “move” in VBAC/VBAMC moms

One large study has found that a previa is less likely to move away from the cervical os if the mother has a history of prior cesareans.  Please go here for more.

Making a plan and moving forward

Your best bet is to review your medical records with several VBAC supportive care providers and get their opinion.  Obtain a copy of your medical records and operative reports from each prior cesarean, get the names of VBAC supportive providers, and ask the right questions.  Read more about planning a VBAC.

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