VBAC success prediction: what really matters?

2686320038_9cd54b12c8As I swim through the birth literature each week as part of my everyday work and to find things to highlight in my birth information project, it’s probably inevitable that I notice trends, and a recent trend relates to the question of whether we can predict which women will have successful vaginal births after a previous caesarean (VBACs).

If you were hoping for an analysis of that literature, then I’m going to disappoint you, because that’s not where I’m going today. (That doesn’t mean I won’t look at it one day if there’s enough interest, but I haven’t done so yet). What I want to share today is my concern that these studies aren’t taking a wide enough view.

As in so many areas, well-intentioned researchers are seeking out physical, measurable factors which might make a difference here. I guess the thinking is that, if we can show that women who decide to birth in a particular hospital or who wear size six shoes or who eat cucumber sandwiches three times a week have a higher chance of a successful VBAC than women who don’t fall into those groups then that might help us counsel women about their chances of a successful VBAC. Or it might help us begin to look at what women can do to increase their chances of a successful VBAC.

In reality, such thinking is fraught with pitfalls. The association of two factors (such as successful VBAC and cucumber consumption) might mean nothing at all, and it is not necessarily the case that encouraging more women to eat or do certain things will make any difference to their chances.

20777294038_c8885ef9ffBut, important as that point is, that’s not where I’m going here.

When one is carrying out quantitative research, one needs to look at things that are measurable. But, as we know, the important things in life often aren’t measurable.

If you asked me, as an experienced midwife, what I think makes a difference in a woman’s chance of having a successful VBAC, this is what I would tell you. I have no evidence to base this on, but my experience tells me that one major factor in VBAC success is the extent to which a woman has processed her previous experience, figured out what might have gone awry and why, considered whether there are things that might make a difference next time around (which is not, by the way, always the case, lest you think I’m saying otherwise) and, if possible, put things in place to help make that difference.

A woman who felt she didn’t have the right people around her the last time might, for instance, look for caregivers who are supportive of her wishes and needs. A woman who felt that the environment might have been part of the issue might make a plan to birth in an environment where she will feel safe but not doubted. I also meet women who have, at some point in between their first and second birth experiences, become birth warriors; entering their second birth with considerably more confidence and self-belief than their first.

Trouble is, some of those measures aren’t very measurable, so they’re not being accounted for in the studies in this area. Again, these are by no means the only factors, and please don’t think for a moment that I’m suggesting that measureable, physical factors aren’t an issue, because they clearly are. But it would be truly lovely if we could acknowledge other dimensions as well.

photo credit: The cats study physics with me. via photopin (license) and Humboldt County via photopin (license)

3 comments for “VBAC success prediction: what really matters?

  1. Nymphadora
    March 10, 2016 at 1:56 pm

    Very interesting article. I am a midwife working in the NHS and I find that 2 factors do matter in predicting success of VBACs: 1) having a supportive team around you that believes women can labour spontaneously and normally after a caesarean, 2) the use of intermittent auscultation as opposed to continous monitoring.
    This team of independent midwives in Spain “Néixer a casa” (sorry the attached article is in catalan, but you can translate with google translator), are specialised in VBAC and VBA2C, and have a repeat caesarean rate of 3%. About 40% of the women they attend have a previous caesarean, and they have attended hundreds of VBACs at home. This deffinitely differs from the rates of success commontly cited in the literature (75%). However, in the studies included in the well known studies, tipically would have women attached to a CTG, limited movement during labour, and they provide very little information about use of epidural .
    http://www.neixeracasa.com/home3/index.php?option=com_content&view=article&id=114%3Apvdc-parto-vaginal-despues-de-cesarea-anterior-en-casa&catid=39%3Aarticulos&Itemid=99&lang=ca
    In a hospital setting things look a bit more grim for women wanting a VBAC, as normally guidelines recommend use of continuous monitoring, and I would add, the obstetric team often pushes for an “early epidural, just in case we have to rush to theatres”, implying with that, that they don’t trust at all women’s ability to birth naturally after a caesarean.

    • May 11, 2016 at 5:17 pm

      Agree wholeheartedly. As a home birth midwife my stat are encouraging with a successful VBAC rate of 94% and most of these at home http://www.kentmidwiferypractice.com/our-stats/

      Place of birth matters…wherever that is for each particular woman – hospital birth centre or home

  2. March 28, 2017 at 7:21 pm

    Love this, have met some amazing birth warriors along the way, women who know their own body’s strengths and limitations and the wisdom to know the difference <3

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