Sydney Pelvic Floor Health


Vaginal Birth after Caesarean (VBAC)

Attempting a vaginal birth after a first birth by Caesarean is called ‘VBAC’ or ‘TOLAC (trial of labour after Caesarean). It’s very topical right now because it’s one of the few options we have to lower the Caesaran Section rate, and if you’re reading this you probably know that lots of people think that that’s a good idea. I disagree, but that’s another topic.

There are now dedicated clinics in many hospitals as part of antenatal services. If a patient books for antenatal care and her first baby was born by CS, she will likely be given an appointment in a VBAC clinic. This means that someone, usually an obstetrician, will discuss the pros and cons of trying for a normal birth with this second pregnancy. Some women may not be eligible, eg if they have high blood pressure or diabetes, others will prefer a repeat CS, and usually the decision is left to the patient.

In some places, especially hospitals where management and senior clinical staff ‘buy into’ the ideology of natural childbirth, there may be a lot of bias in the information provided to patients. I have no problem with women making such decisions for themselves- it’s not up to doctors or midwives to tell women what to do. But such an important decision needs to be reached on the basis of accurate and up to date information, and that may not be the case everywhere and at all times.

A recent research paper, “Improving VBAC rates: the combined impact of two management strategies” published in a journal I work for, the ‘Australian and New Zealand Journal of Obstetrics and Gynaecology (ANZJOG), makes that point very clearly.

The authors report on a series of 396 VBAC candidates who attended a dedicated clinic. The stated goal of this clinic was, as required by the Health Department of New South Wales, Australia, through the policy directive “Towards Normal Birth”, to increase VBAC rates, with the aim of reducing CS rates. The authors convinced 57% of candidates to attempt VBAC, although about 10% of them changed their mind, and only 160 actually went into labour. Of those 160, only 75 managed a normal delivery and both Vacuum/ Forceps (17.5%) and emergency C/S rates (35.6%) were very high.

What s more important is that there were two deaths. One stillbirth after the due date and one as a consequence of a ruptured uterus, a well- recognized complication of laboring with a womb that bears the scar of a previous CS. This may be more common now than what’s stated in the textbooks because we tend to push labour harder than 10 or 20 years ago, and many hospitals now use Syntocinon to make contractions stronger, something that would have gotten me fired if I had done that as a junior doctor in the late 80s or early 90s. VBAC caused the death of those two babies, and it endangered the life of at least one mother rather seriously.

The authors do point out that “we must be mindful that pursuing increased VBAC rates…might have significant costs such as increased uterine rupture rates.”- but they don’t mention those two deaths in the abstract, nor are they mentioned in Conclusions. Quite on the contrary. They conclude: “A dedicated NBAC clinic and more consistent approach to labour management can help improve VBAC rates,” and “Further targeted counselling towards women with previous malpresentation and/or East Asian descent may further improve VBAC attempt rates.” Yes, let’s try and talk more people into VBAC then.

I asked the authors, publicly and in writing, whether they’d share that information- a likelihood of 1:100 of their baby dying if they opt for VBAC – with their future patients. They didn’t answer. This touches the issue of ‘informed consent’. Nothing we do is legal without informed consent. The patient has to agree to the proposed course of action, in this case VBAC, and that’s valid only after she has been fully informed of possible consequences, including the death of her baby. Without informed consent our interventions may be politically correct and they may well comply with government policy directives, but they will be illegal.

What on earth are we doing this for? Why all this misguided effort? Why are well- trained and competent obstetricians risking the lives of their patients, and ultimately their own careers? Do C/S rates (or rather, compliance with ill- advised bureaucratic targets) matter more now than actual dead babies?

From my point of view it does not matter whether you decide to try for a normal birth after a Caesarean or opt for a repeat CS. The balance of pros and cons will vary a lot from one person to the other, and the decision must be yours, except in rare circumstances where that’s impossible. However, midwives and doctors are legally required to give you the full story. Withholding information is dangerous, not just for the mother and her baby, but also for those who look after her in antenatal clinic and delivery suite.

HP Dietz