VBAC Risk and Safety: In the Eye of the Beholder?

[As part of my childbirth educator certification, I needed to read research and write a report on VBACs (vaginal births after cesarean). The following is that report, consisting of a small piece of the issues raised through my reading of this research. Resources (information and VBAC/HBAC stories) at the end of the post.]

“Studies show” VBAC risk and safety are in the eye of the beholder.

Studies have real implications on people’s (mothers’) actual lives. More and more women and families are impacted by VBAC studies and their authors’ interpretation of data. Data shows that current practices and technologies are not only unhelpful but in some cases actually harmful to mothers and babies. Yet, many hospitals and doctors (and midwives?) continue to believe (and thus pressure or “encourage”) mothers to have repeat cesareans. 

If you are a VBAC/HBAC (home birth after cesarean) mother, you might wish to look into how care is managed for trials of labor at a hospital with a doctor/midwife as well as interview a homebirth midwife, asking how she would handle various scenarios, to have a point of comparison. YOUR birth. YOUR choice. 


Vaginal birth after cesarean (VBAC) seems to be a hot button topic now, and with one in three women giving birth by cesarean section I believe this will only continue to become more prevalent in the general conversation. As more and more women get cesarean sections, more will be getting repeat cesarean sections as the rule of “once a cesarean always a cesarean” reigns. Of course uterine rupture is the focus of the day, so I was very interested in finding out what the article in The New England Journal of Medicine by McMahon, Luther, Bowes and Olshan had to say about trials of labor versus elective second cesarean section.

The authors concluded that birthing mothers who chose a trial of labor had twice the likelihood of having major complications, namely uterine rupture and hysterectomy. Their suggestion is to decrease risk of maternal complications by imposing limits for who can choose a trial of labor. They point to their results that “women were more likely to have a successful trial of labor if they were 35 years of age, if the child’s birth weight was less than 4000 g and if they delivered in a tertiary care hospital.”

These conclusions seem somewhat incongruent with the actual findings from the authors’ own studies and raise questions about the overall care and belief surrounding women seeking VBACs. In the results section the authors state “Most of the complications, however, were minor and were more likely to occur in women undergoing an elective cesarean section than in those undergoing a trial of labor.” Also, their research showed that “Elective second cesarean section was twice as likely to occur at a regional hospital as at a tertiary care hospital” and even more likely at community hospitals. This, put together with their own conclusion that VBACs were more successful at tertiary care hospitals raises the question about the care given and methods used at regional and community hospitals. Additionally, prenatal classes increased the likelihood of VBAC success. Furthermore, they specifically state that major complications were more likely “for women who had a second cesarean section without a previous trial of labor.” All of this seems to point not only to many positive outcomes for mother seeking VBACs but to the fact that the way care is being “managed” may be causing the problems in the first place.

If I had to summarize all that I read in these three studies plus the abstract and letters to the editor and the reply, it would be that perspective is everything.

While the data seems to be within a relatively consistent range, the interpretation and conclusions based on the data vary widely. My sense is that this variance in recommendations is a factor of the bias and belief of the authors themselves. What is “acceptable risk,” which risks are to be prioritized and avoided, and even who is more important (baby or mother) all shape interpretation and suggestions when considering the safety of vaginal birth after cesarean.

For instance, the most major complications feared for VBACs require special care, equipment and staff. Indeed, “normal” vaginal births and VBACs both have risks that require this kind of care, ideally if one follows the line of thinking presented by researchers discouraging out of hospital VBACs. By admission, many hospitals are ill equipped to deal with these any complications requiring immediate attention. Yet these same issues are overlooked when considering birth as a whole. What is acceptable risk to some researchers for a “low risk” birth becomes a limiting factor in the choices of VBAC-seeking mothers.

I understand that death of a mother or a baby from major complications is the ultimate fear, but something I felt was omitted in the consideration of VBAC safety was the impact of all those “minor” complications. One example is risk of fever in the mother which was significantly present (25% higher) in elective cesareans. These are classified as minor complications, but they have a marked impact on the life and relationship between mother and baby in the postpartum period and beyond. This is particularly clear if one considers some hospital policies that separate mothers with fevers from their babies. This often requires baby to be given formula, which along with disrupting the breastfeeding relationship also has been proven to disrupt the delicate digestive flora and ultimately the immune system of the baby for an undetermined length of time. I believe the overall health and well-being of the duo (mother and baby) should be considered.

One last thing that was on my mind reading the studies and letters was the reality behind the numbers. There is evidence that a birthing mother’s emotional state and mental belief can influence labor, as found by birthworkers such as Ina May Gaskin. These more subtle, unmeasurable factors could have a bigger effect than expected. For instance, when the studies say women were “encouraged to consider trial of labor” by their doctors I wondered what that actually sounded and looked like. I wondered things like how many women choosing a trial of labor were exposed to negative talk about the baby or the birth or their body. VBAC mothers, and particularly those carrying larger babies, seem to be the most prone to additional, and possibly unnecessary or inaccurate, poking and prodding. I know these factors are not “scientific,” but I can’t help but wonder the effects of the relationship between caregivers and mothers for better or worse.

Overall, the articles pointed to some common complications, both major and minor, that could be addressed by means other than narrowing the limits for who can have a trial of labor. For instance, induction turned up as a factor for some of the “failed” trials of labor. More could be examined using similar methods of data collection evaluating the outcomes for trials of labor in which labor is induced. This may show that induction should be particularly avoided in mothers choosing a trial of labor after a previous cesarean. Certain topics may require more research as they pertain to cesarean sections and VBACs specifically, but they include delaying cord clamping which may be found to help strengthen 1 min and 5 min Apgar scores in babies that concern some researchers, reconsidering use of electronic fetal monitoring which has shown no reliable benefits or limiting vaginal exams to reduce risk of infection.

In the end, the data raises the question: What can we do based on what we know? The authors of the The New England Journal of Medicine article or the Lieberman et al study would say we should continue to impose stricter limits on birth choice and method to avoid certain complications that they have prioritized and emphasized. However, a more holistic view might yield more holistic solutions. There are alternatives to repeat cesareans as a rule or a heavily managed hospital birth as the only option; these alternatives should be examined. With a healthy respect for women, babies and birth that research could be used to lower the risk of complications as well as address the complications themselves, all while allowing women who have had a previous cesarean section more choice and access.

YOU Make Your Choice. Know Your Options.

(One of my favorite birth videos: “This is the story that details the traumatic cesarean birth of my first daughter Dylyn and the journey of becoming a Doula, Childbirth Educator & Midwife in it’s aftermath. It ends with the Home Water Birth of my son River.”)





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