Mama Bird's Quick Guide to: VBAC


When you find out you’re pregnant after a previous caesarean, it can be daunting and difficult to navigate your birth options. Almost certainly at your booking-in appointment you were told you were “high-risk” and immediately put under consultant-led care. Maybe you have attended consultant appointments and been told how you will be giving birth.

I wanted to write something to summarise the information I usually give mums planning their VBAC (Vaginal Birth After Caesarean) from my experience of supporting them. I will also be writing a guide to caesarean for those who decide this is the right option for them too. 

VBAC is a safe and rational option and NICE guidelines state that women should be supported in this choice for up to 4 previous caesareans. Often mums are treated like one big walking risk, but I want to get specific….

What are the main risks?

What is not always explained to mums is that when they have a caesarean this impacts future pregnancies. One of the risks is placenta accreta where the placenta attaches abnormally into the womb and can increase the rate of haemorrhage and miscarriage. The other risk is placenta previa which is where the placenta covers the cervix. These risks increase with each caesarean.

The main risk usually talked about is scar rupture and this is the basis on which caregivers usually plan a mother’s labour for her. The risk of rupture is 0.5%, that is, 1 in 200. Of that 0.5%, 6% of those ruptures are considered “catastrophic”, which is to say, resulting in perinatal death.

Induction of labour may not be recommended as the synthetic oxytocin (syntocinon) may increase risk of rupture so it’s important to make a plan should you go “post-dates” whether you would prefer to have a planned caesarean section or try other methods of induction with their associated risks.

For these reasons caregivers usually recommend giving birth in a consultant-led unit and having continuous monitoring, as any variations in the baby’s heartbeat are early indicators that a rupture may occur. 

What makes VBAC less likely to happen?

Continuous monitoring and being in a consultant-led unit both reduce the chance of a VBAC as they increase the risk of intervention. Currently there is no evidence that continuous monitoring improves outcomes over intermittent monitoring via Doppler. Continuous monitoring reduces the ability to move and have an active labour.

If you wish to have continuous monitoring, the alternatives are a fetal scalp monitor or wireless monitoring which would enable you to use a birth pool. However, the scalp monitor requires your waters to be broken (which is an intervention) and the wireless monitoring may not be reliable or caregivers may be reluctant to use it. You can request intermittent monitoring and a waterbirth on the consultant-led unit if a pool is available.

The chance of a successful VBAC in this setting is around 60-80%, which is about the same as the chance of any first time mum having a vaginal delivery.

What makes VBAC more likely to happen?

The rate of successful VBAC in a home setting has been reported to be as high as 90%. The benefits of being at home are that you have minimal risk of intervention and are in control. Some women make this decision based on how close they live to their local hospital if an emergency occurs.

Having a doula reduces the risk of caesarean section.

If you don’t want to give birth at home or on a consultant-led unit, a compromise may be a midwifery-led unit, or MLU. However, they do not usually accept VBAC and it is up to you to negotiate if that is where you would like to give birth. They may not say yes. You will need to make an appointment with your head of midwifery or consultant midwife and if necessary, get your birth plan agreed and signed so you do not have any problems on the day when you arrive in labour.

Your greatest asset will be a strong birth partner and advocate for when you are in labour to speak up for what you want when you may not be able to.

When negotiating - ask for facts, just like I have given you. Any emotional blackmail or incorrect information is unacceptable. If you decide that VBAC is right for you and you have anybody who is unsupportive, you are entitled to decline their care and request somebody else. Ask yourself - who prioritises the baby's safety more than the mother? Nobody. Your job is to make the decisions that are right for you and birth in the manner in which YOU feel safest. 

Any additional risk factors beyond previous caesarean will need to be taken into account when making your decision. However, you can feel confident that VBAC is successful the majority of the time.

Remember this is YOUR body, YOUR baby and YOUR birth.