VBAC/TOLAC - choice or coercion
Updated: Aug 10
A quick warning, this is a long post, reflecting the gravity of the topic. Also, these are my own thoughts. Take them or leave them and leave it at that. I should also stress at the beginning that I am very supportive of women attempting VBAC. That is not what this blog is about. This entry is an exploration of the challenges inherent in counselling about VBAC.
Anybody involved in women's healthcare or following any one of a number of blogs, podcasts, Instagram feeds or other social media forums that offer up commentary and advice on women's health will no doubt be aware of the tension that exists between the medical establishment (ie. obstetricians) and certain members of the midwifery and alternative healthcare professions. Note that I said certain members as by no means am I suggesting that this tension is universal, nor am I suggesting that it is by any means a one way street. One area of controversy relates to the topic of vaginal birth after caesarean section (VBAC or TOLAC - trial of labour after caesarean).
Why this is controversial is a topic that entire essays could be written upon and still not completely address the underlying origins as to why tension often seems to arise between the medical advice to women and that provided by other sources. Suffice it to say, from individual clinicians to entire healthcare systems, the question of whether a woman should attempt VBAC after a caesarean delivery* is not always one that is, in my opinion, a question honestly posed to women.
(*yes, I am aware that the phrase "VBAC after caesarean" is akin to "ATM machine")
Let me explain.
First of all, my own view on the issue. Put simply, it is a woman's choice; not mine, not her midwife's, not her hypno-birther's or doola's, certainly not her best friend's or her mother's. This seems a self evident statement at first glance. But, if one truly believes that this is true, then the woman in question has to be afforded the opportunity to make an informed choice that is in her own personal best interests. Those interests will be informed by a myriad of factors, often not entirely medical in nature, and certainly not conducive to a one size fits all approach to counselling. As a clinician frequently involved in such counselling, I try to ensure that three questions are addressed in the first instance:
When contemplating delivery, what is the woman's first instinct in terms of how she would like to deliver?
What are the comparative risks involved in her two options - ie repeat caesarean section or VBAC?
If she does wish to attempt a VBAC then two further questions become important:
What is the best estimate of her prospects for successful vaginal delivery? - a question all too often left out of counselling. Reasonable algorithms exist that allow us to provide an estimate of likely labour success and this likelihood of success is information that a woman is entitled to - and telling someone that they have a relatively low likelihood of success is not the same as saying that they either shouldn't try or have no chance of success;
What would she like to do in the event that induction of labour becomes a consideration? - as this almost doubles her risk profile as regards scar integrity.
It is how the above questions are posed to women that creates the tension in women's healthcare. On the one hand, obstetricians are accused of over-stating the risk associated with VBAC, leading to accusations that we effectively coerce patients into having repeat caesarean sections due to the creation of a climate of fear. I'm sure this does happen, in poor obstetric practice. Thankfully, I remain confident that this approach is not reflective of that adopted by the majority of obstetricians, both in public and private practice. The retort from obstetricians is, of course, that risk is down-played too much by those who are critical of the obstetricians and that this down-playing of risks leaves women ignorant of the potential consequences of the same, and in their own way coerced into a course of action they might not otherwise have taken. This is a dichotomy that I have spent some time considering. Not in order to resolve the tension that exists between well meaning healthcare workers - I am no Solomon. Rather, it is to ensure that I am able to provide advice that is honest and, as far as possible, untainted by my own experiences - this last is the challenge as all human beings are influenced by their past experiences and it is difficult to ensure that those experiences don't overly colour the advice provided. In a sense, this is the saving grace of statistics as they relate to risk. As an obstetrician we can seek refuge in the presentation of the numbers, respecting two important factors:
Risk is a personal construct - what one person is comfortable adopting, another may regard as outrageous;
Women come to us for the benefit of our training, expertise and experience. It is therefore incumbent upon us to ensure that the risks are presented in a fashion that is relatable to the woman and to explore the factors that either mitigate or increase that risk.
So what are we even talking about anyway? What are the risks and how do the two options (elective repeat caesarean section vs VBAC) compare? A full description of all risks is beyond the scope of this blog, however, a broad brush stroke of the basic risks is worth elucidating - these numbers are an amalgam of available studies and institution specific numbers reflecting the hospitals that I practice in:
Elective caesarean section
Actually a relatively safe surgical procedure, which is not to say that it is not major surgery. What I call the big ticket items are roughly:
1:1000 - on the table haemorrhage requiring blood transfusion; bladder injury requiring repair and prolonged catheterisation (typically 10-12 days);
1:10,000-50,000 - other visceral injury, including bowel injury and uterine trauma requiring hysterectomy (this last is not unique to caesarean deliveries);
Placental accreta/percreta - repeat caesarean sections are associated with an increasing risk of placentation abnormalities (specifically abnormalities where the placenta grows abnormally into the wall of the uterus). Pragmatically, it is reasonable to say that this serious concern rises significantly from the third or fourth caesarean section, hence the standard advice to consider completion of your family after three caesareans.
Recovery - extremely difficult to predict, but it is fair to say that women who manage an uncomplicated vaginal delivery will recover somewhat quicker than women who undergo caesarean section. That said, I do have to say that in my own practice the majority of women who undergo an elective caesarean section are generally managing quite well when I see them a week after discharge.
Possible neonatal and long-term developmental differences - there is an emerging body of evidence in the paediatric literature that examines long-term differences between babies born by caesarean and those born vaginally. Exploring this literature in detail would require a whole other blog entry. My own take on the literature is that there are a range of confounding variables that make application of this data to the individual woman problematic. As I say to my own patients, a teacher standing in front of a class room cannot point to one child and say "he/she was a caesar baby".
It's all about the scar. As I tell my junior doctors, 'respect the scar'. Having undergone a caesarean section, women presenting in a subsequent pregnancy now have a band of inelastic tissue running through the middle of their otherwise elastic lower uterine segment. The way that I explain this to women is to first explain the natural properties of the lower segment. This can be thought of as the immediate uterine continuation of the cervix and, like the cervix, it undergoes significant stretching in order to allow for the unborn foetus to be delivered. After a caesarean section there is now a band of scar tissue in the middle of this segment. Unlike healthy tissues, scar tissue does not stretch, it holds. The question then becomes, what is the risk of that scar tissue giving way during labour - an event called a uterine rupture - and what are the consequences of such an event?
1:200, or 0.5% is the standard number quoted. This increases to 1:100-150 with induction of labour, hence the questions that I mentioned previously. A variety of other factors can also increase this risk, including any complications that may have arisen during the sentinel caesarean delivery. And what if someone is unlucky enough to be that 1:200?
As with many aspects of women's healthcare, a range of numbers are generally quoted. Generally speaking, I do feel that the following is a reasonable presentation of the potential consequences should a woman be unlucky enough to suffer a uterine rupture - 5-10% foetal demise, 20-40% survivors with permanent neurological injury, 5-10% of women requiring a hysterectomy, 20-40% of the remainder suffering massive blood loss requiring transfusion and possible ICU admission.
There are a variety of other risks and considerations that need to be factored into any individual woman's counselling and decision making. And of course, it is not all about risk. The unique desire amongst many women to not only experience labour but achieve a successful vaginal delivery goes well beyond simple statistics and risks. Ultimately, the task of counselling a woman should be to empower her with the information that she needs to make the decision that is right for her.
This brings me back to the heading of this blog - "choice or coercion".
Is it coercion to provide a woman with the facts, tailored to her particular circumstances? Or is that empowerment? Is it frightening a woman to tell her that things can go wrong? Or is that respecting a woman's own agency and right to self-determination? If a woman elects to have a repeat caesarean section is she a victim of medical interference, undermining her faith in her own body? Or is she an adult making a considered decision that is right for her and that has been informed by the information presented?
There is a phrase that gets bandied about around women's healthcare circles - "woman centred care". This is a wonderful sounding phrase and is supposedly predicated on the idea that women be empowered to take control of their own healthcare and pregnancy journey. Unfortunately, I have come to the conclusion that in certain circles, including at the level of state health departments, so called woman centred care is more about enforcing conformity upon women without respect for their individual motivations. Too many commentaries are freighted in negative language that piles guilt upon the shoulders of women who do not conform to the image of womanhood that is being dictated to them by various elements within society. The woman who succeeds against the medical odds is to be applauded, while the woman who has an elective caesarean section for her first pregnancy is "too posh to push". I am not sure what the solution is to this judgemental approach to women's well-being. What I am sure of is that it is incumbent upon all clinicians caring for women in pregnancy to strive to work positively together, to park their own prejudices at the door, and to remember that the journey towards childbirth belongs to that woman and no-one else.