VBAC (vaginal birth after caesarean) is big. A google search for ‘vbac’ results in ‘about 795,000’ results. Reviews, guidelines, policies and statements are being produced by every organisation with an interest in birth. Support groups and networks are growing. I am not going to add to this wealth of information. Others are doing a fantastic job and I will provide some links at the bottom of this post. This post is really aimed at putting VBAC into perspective risk-wise and discussing how we can best support women planning a vaginal birth after caesarean. I haven’t personally experienced the VBAC journey and would welcome some input from mothers who have via comments, suggestions and links. This is written from my perspective as a midwife.
With a c-section rate of around 1 in 3 (Australia) a significant proportion of women approach their subsequent birth with a scarred uterus. Of those women, 84% will have another caesarean. I can’t find the stats re. how many of these repeat c-sections are planned vs emergency. But, considering the 50-90% ‘success’ rate for VBACs, I am assuming that most repeat c-sections are planned. I wonder if more women would choose to experience a vaginal birth if they had adequate information and support from care providers who believed in them?
Guidelines suggest that women should be counselled about the risks of VBAC, and they should have additional monitoring and intervention during labour. The big concern is uterine rupture, and this is what I am going to focus on. By the way – unless I provide a reference/link you can assume I am getting my numbers from the NIH Consensus Statement (US) or Having a Baby in Queensland (Aus). Both of these resources are based on current research evidence. So, if you need the original research sources check out their reference lists.
What happens during a uterine rupture?
Considering this is the risk associated with VBAC is worth briefly describing what is involved. Uterine rupture can happen at any birth, even when no scar is present (particularly if syntocinon is used). There are two types of uterine rupture associated with VBAC (Pairman et al. 2014):
- Catastrophic (symptomatic) – the old scar separates long its length, the amniotic sac ruptures and the baby is pushed into the abdominal cavity. This results in significant bleeding, shock and the baby is in grave danger.
- Asymptomatic – the scar separates partway along its length, the amniotic sac stays intact and the baby remains in the uterus. Bleeding and shock is minimal and the baby usually survives. This is the most common type.
Risk by numbers
Risk is a difficult concept. You can have odds of 1 in a million, but if you are the 1 it is 100% for you. It’s also impossible to eliminate all risk from life (or birth) and every option has risks attached. All women can do is choose the risk that feels right for them – there is no risk-free choice. There are many ways of presenting risk and some ways may mean more than others for individuals. For example, if we look at the overall risk of uterine rupture for a woman who has had 1 previous c-section. By overall, I mean without adding or subtracting factors which increase or decrease an individual’s risk (eg. syntocinon during labour, transverse scar). The risk can be presented like this:
- 50 out of 10,000 will rupture
- 9,950 out of 10,000 will not rupture
- 1 in 200 will rupture
- 199 out of 200 will not rupture
- 0.5% will rupture
- 99.5% will not rupture
Which of these versions would help you conceptualise risk? I know when I look at the picture versions of risk I assume I’m the ‘red person’. Personally I like the 99.5% intact uterus odds.
As stated above these figures are the taken from the NIH Consensus Statement (US) or Having a Baby in Queensland (Aus). A more recent UK study (Fitzpatrick et al. 2012) found an even lower overall risk of rupture – 0.2%.
The risk of rupture may be even lower in labours that are not induced or augmented (the stats above are a mixture of all labours). An Australian study (Dekker et al. 2010) found that the risk of uterine rupture during VBAC was 0.15% in spontaneous labour, 1.91% in augmented labour and 0.88% in labour induced using prostin and oxytocin. Fitzpatrick et al. (2012) also found an increase in rupture with induction and augmentation. In contrast a US study (Ouzouian et al. 2011) found no different in rupture rates between spontaneous and induced labours – but found a significantly greater vaginal birth rate following spontaneous labour. Another study (Harper et al. 2011) found an increased chance of rupture during induction when the woman has an ‘unfavourable’ cervix. There are also other risks associated with induction which need to be considered before heading down that pathway.
For women who have had multiple c-sections: Landon et al. (2006) suggest the risk of rupture rises to 0.9%. Fitzpatrick et al. (2012) also found a slight increase in risk for women how had had 2 or more previous c-sections. However Cahill et al. (2010) found that: “Women with three or more prior caesareans who attempt VBAC have similar rates of success and risk for maternal morbidity as those with one prior caesarean, and as those delivered by elective repeat caesarean.”
The story looks a little different again when you look at the mortality and morbidity caused by uterine rupture. Guise et al (2004) conducted a systematic review of research relating to VBAC and uterine rupture. They found that uterine rupture resulted in: 0 maternal deaths; 5% perinatal deaths (baby); and 13% hysterectomy. They conclude that: ‘Although the literature on uterine rupture is imprecise and inconsistent, existing studies indicate that 370 (213 to 1370) elective caesarean deliveries would need to be performed to prevent one symptomatic uterine rupture.’
So, out of the small number of women who experience uterine rupture, an even smaller proportion will lose their baby or uterus because of it. When the uterus ruptures 94% of babies survive. The RCOG guidelines state that: “Women should be informed that the absolute risk of birth-related perinatal death associated with VBAC is extremely low and comparable to the risk for nulliparous [first baby/birth] women in labour.”
VBAC vs planned c-section: uterine rupture
Most resources and guidelines compare the risk of a VBAC with the risks of a repeat c-section. This can be a brain-twister because of the multiple and complex risks associated with c-section for mother and baby. Childbirth Connection cover them well, so I won’t. It is also important that women know a c-section increases the chance of stillbirth in subsequent pregnancies (Moraitis et al. 2015). Having a Baby in Queensland directly compares VBAC with planned repeat c-section for a number of complications.
I’m trying to stick to the risk of uterine rupture (the ‘big’ one). So, planned c-section wins with a 2:10,000 uterine rupture rate compared to 50:10,000 for a VBAC. That’s if you are happy to take all the (more frequently occurring) risks associated with c-section in exchange.
Uterine rupture vs other potential birth emergencies
A Woman’s Guide to VBAC: Navigating the NIH Consensus Recommendations compares uterine rupture with other potential complications. You are more likely to experience a placental abruption, a cord prolapse or a shoulder dystocia (not associated with previous c-section) during your vbac than a uterine rupture. Your baby is also more likely to die from the placental abruption or cord prolapse than from a uterine rupture.
Anecdotes often hold more power than numbers. I can guarantee that I will get a comment telling me about a poor outcome associated with a VBAC. They do happen (see the stats above). Unfortunately when care providers have been involved in a traumatic situation, it can be hard not to let that experience colour their perspective and approach. The memory of one uterine rupture will be stronger than all of the uncomplicated VBACs they have seen. The only uterine rupture I have personally been involved with was an induction of labour – not a VBAC. So, I emotionally associate uterine rupture with induction rather than VBAC.
Obstetricians in particular have to deal with the fall out of major complications because this is their area of expertise. They also miss out on seeing physiological births which end well because this is the realm of the midwife (I know this is different in the US/private sector). This can lead to fear-based counselling and practice, and a general fear of normal birth. It is interesting that a poor outcome associated with a c-section does not seem to elicit quite the same response – ie. fear of c-section.
When parents find themselves the 1 in how ever many, it is even more devastating. Their stories are powerful and need to be heard. However, it can be difficult for other parents to contextualise the story without also hearing stories with good outcomes.
The real risks of VBAC (according to me)
I am a bit confused about why such a huge deal is made about the risk of uterine rupture during VBAC. Why are these women subjected to serious (and often biased) discussions with fearful practitioners about the dangers of attempting birth? Why are they categorised as ‘high risk’, limiting their care options and imposing additional monitoring and intervention during their labour? If we agree that this is the right approach, then we also need to treat all women like this because the risk of placental abruption or a cord prolapse is greater than the risk of a uterine rupture during a VBAC.
To be honest, as a midwife uterine rupture is the least of my worries when caring for a woman having a VBAC. I actually think the mountain that has been built out of the risk-molehill requires more energy and attention. These women do need special treatment, but not in the form of disempowering fear-based counselling or practice. They have often had a previous traumatic birth experience and are dealing with fear from family, friends, and the medical system, in addition to their own worries. They have been labelled ‘high risk’ and are constantly reminded of the potential disaster waiting to occur. They also risk ‘failing’ if they encounter any complications or end up having a repeat c-section. This impacts on their ability to trust their body, follow their intuition and allow the physiology of birth to unfold. Often these women need more nurturing, reassurance and support from those involved in their birth.
It is important to not only help women to prepare but also their partners and/or other close family members who may be at the birth. Often the partner was present at the previous birth, which may have been traumatic to witness. For a partner their priority is the safety of the woman they love – not a particular birth experience. Winning them over may be difficult. In some cases the decision the mother makes may be that the partner should not be present. OK – some suggestions:
- Find out the details of her previous birth experience. If she needs debriefing help her do so, or refer to someone who can. Knowing about her previous experince and her fears can help you know what she needs during her labour.
- Offer to discuss ‘risk’ and present the statistics in a number of ways. Find out what they (mother and partner) find most useful and empowering. I could say ‘don’t mention risk’ but to be honest ,unless she is living in a cave she will already be aware that VBAC is ‘risky’ and will need to explore this. In addition, it is a legal requirement for midwives to provide evidence based information about risk.
- Make sure she is aware that she has a very good chance of having a vaginal birth – 72-75% if she has not previously had a vaginal birth, and 85-90% if she has (RCOG). Overall, she has a greater likelihood of a vaginal birth than a woman having her first baby and no previous c-section.
- The RCOG guidelines state that: “Women should be made aware that successful VBAC has the fewest complications and therefore the chance of VBAC success or failure is an important consideration when choosing the mode of delivery.” Therefore it is important to consider previous birth scenarios and contexts to evaluate the chance of success for the individual woman.
- The woman also needs information about factors that can increase her chance of VBAC eg. choosing supportive care providers (and setting) and not having her labour induced or augmented.
- Talk about the possibility of the pregnancy going beyond the prescribed ‘due date’. This is often a feature of VBAC pregnancy. Some hospitals or midwives consider this to be a risk factor because the chance of a repeat c-section is about 9% greater (Coassolo et al. 2005). However, the risk of uterine rupture is no greater.
- Make sure she knows that having a c-section after labour has started holds more health benefits than a planned c-section. Her baby will have had a chance to initiate labour and make the physiological changes needed for life outside the uterus. They will be less likely to suffer respiratory distress and end up in special care (Senturk et al. 2015). In addition, both mother and baby will have the important cocktail of hormones that assist with bonding. Even if she chooses a repeat c-section she can insist on going into labour first.
- Talk to her and her partner about what actually happens if the uterus ruptures. They may be imagining all kinds of horrific scenes such as the baby bursting out of an exploding abdomen.
- If she is worried about ‘failure’ reassure her that she doesn’t need to tell anyone she is planning a VBAC. She can say she’s not sure and will decide in labour.
- If she is planning to birth in hospital she needs to know what the hospital policies are and decide what she will or won’t go along with. This means talking about the risks of the usual interventions such as CTG monitoring. A very clear birth statement can help the staff to support her wishes. It might be helpful to find out the VBAC rates at the hospital to gain some idea about how supportive they are likely to be during labour.
- Encourage her to talk to other women about their experiences of VBAC, read positive birth stories and watch beautiful VBAC birth movies.
- Do not use disempowering language such a ‘trial of scar’ or constantly refer to her birth as a VBAC. She is a woman having a baby, not a disaster waiting to happen.
The physical care of a woman having a VBAC should be no different (although I know it often is in hospital). Yes, I’m watching for signs of a uterine rupture: unusual pain, unusual contraction pattern, fetal heart rate abnormalities, unusual bleeding, a change in maternal observations etc. But, those symptoms in any birthing woman would be concerning, so this is not different care. In addition, if a woman is unmedicated and connected to her body/baby she will usually be the first to notice a problem. I have found that women having a VBAC may have additional psychological needs. For example, they may request vaginal examinations, particularly if their c-section was for ‘failure to progress’ (aka failure to wait). Even with information about how poor VEs are at indicating progress they may want that dilatation number – some non-VBAC women do too. They may also want more frequent fetal heart rate auscultation to reassure them the baby is well. In general, these women, and even more so their partners need reassurance and a birth attendant who believes in them. Of course some women don’t need any of this and choose freebirth.
Is homebirth a safe option for VBAC? No – birth is not ‘safe’ regardless of the setting. Different risks are associated with different options. In hospital there is greater risk of unnecessary intervention and associated complications. At home, if you are the 0.2% and need to transfer, there is the risk of complications due to a delay in medical intervention (including death of baby and/or mother). Bear in mind that this delay may also occur in a private hospital out of hours when theatre staff are not on site. Women also need to be aware that when it comes to homebirth, having a uterine scar places them in a ‘high risk’ category. The Australian College of Midwives classify a previous c-section as ‘B’ ie ‘Consult’ with a ‘midwife and/or medical practitioner or other health care provider’. This does not mean that a privately practising midwife cannot provide care. And the woman can decline a consultation if she wishes. Some midwives appear to be unaware of this, and tell women that they are not allowed to attend VBAC homebirths – this is not true. However, if you choose an eligible midwife, you may have problems securing a collaborative agreement from a medical practitioner so that you can claim medicare rebates for care. Likewise, homebirth services run from hospitals or birth centres may be unable to accept you as a client. Whilst VBAC homebirth is generally not supported in clinical recommendations, many women choose to birth at home. Keebler, et al. (2015) examined women’s reasons for choosing a homebirth after caesarean and the full text is available here.
VBACs are usually immensely healing and empowering for a woman and her partner. I wonder whether this aspect of birth is discussed at the ‘risk consultations’ along with the numbers.
You can read a birth story and watch the film here. I may be biased but this is a beautifully filmed/edited birth: Madeleine’s birth
Here is another couple’s VBAC journey (have a tissue handy). This is the most likely outcome of a VBAC – particularly a homebirth: