Vaginal birth after c section (VBAC), is where a woman gives birth vaginally after having had a previous caesarean.
Many women who have had a previous caesarean are suitable candidates to attempt VBAC in pregnancy. But, this will depend on you, your current pregnancy and the circumstances of your previous caesarean.
To find out more about what makes for a successful vaginal birth after a caesarean, we spoke to Dr Ihab Abassi, a Consultant Obstetrician for the NHS. He told us, "Whether you choose to have another caesarean or vaginal birth after caesarean, both options are safe. However, neither options are without risks. All birth, even for first-time mums, comes with some risk. Advantages of VBAC in pregnancy include better recovery time for the mum (if labour and birth was uncomplicated) and less likelihood of breathing difficulties for baby compared with caesarean."
Vaginal birth after c section
Vaginal birth after c section (VBAC) is currently recommended for the majority of women who have had a caesarean in the following circumstances:
- Singleton baby pregnancy (not a multiple birth)
- No current health problems in the mother or baby
- The baby has reached term (37 weeks)
- The baby is 'presenting' head down during labour (cephalic)
- Mum has only had one caesarean before
- The previous caesarean was uncomplicated with a lower segment, straight scar (not 't' or 'j' shaped vertical or classical scar)
However, you can still try for a VBAC after c section if you do not fit these criteria exactly - it will mean that you need to look at different risk factors with your obstetrician.
The success rate for VBAC attempts that fit the above criteria is good - according to the UK's Royal College of Obstetricians and Gynaecologists (RCOG), around 72-75 per cent of VBACs will succeed. This success rate increases to between 85-90 per cent, if you have already had a successful vaginal delivery.
Source: RCOG Green Top Guidelines for vaginal birth after caesarean
VBAC after c section is also known as 'trial of labour after caesarean'. An assisted vaginal delivery using ventouse (suction cup) or forceps (large metal 'spoons') to help the baby be born after a previous caesarean is also a VBAC.
Choosing to have a VBAC
For some women, having a VBAC after c section is very important to them. They may feel very unhappy about the circumstances of their first caesarean.
These negative feelings can occur even if the caesarean was a planned surgery, but is more common when women have had a "crash" or emergency section.
Research suggests that emergency caesareans can be a large factor in the development of post-traumatic stress disorder.
"Naomi, a mum of three, who had a vaginal in 2016, C-section in 2018, then a VBAC in 2020 - I was very upset when it turned out I'd need a planned caesarean. I felt like I needed to grieve for the birth I wouldn't have. My caesarean was not what I had imagined and I found it quite traumatic. I was so delighted to manage a VBAC with my third, it was so healing to give birth how I'd wanted."
The concept of safety in pregnancy and birth does not just affect your physical health. Many people think "as long as baby is healthy, that's all that matters". Of course, the physical health of your child is absolutely crucial, but your mental and physical health is important, too.
For other women, who had a traumatic vaginal birth, or a traumatic birth that ended in an emergency caesarean, VBAC after c section is a challenging idea. They might want to try to give birth vaginally but struggle with the memories from previous births. There is evidence suggesting that up to one-third of women suffer from birth trauma.
Deciding to opt for a VBAC in pregnancy, or a repeat caesarean is a very personal choice. You have the right to ask for either option. Speak to your midwife and weigh up the benefits and risks and how they relate to your personal circumstances.
Mum of two, Jenny, who opted for a second, elective caesarean in 2022 - "There's no way I would have wanted to go through all that again and it just end in yet another emergency caesarean. For me, it made sense for me to be in control and say yes... I want a caesarean again, but this time on my terms."
Advantages of VBAC after c-section
The advantages of a VBAC after a caesarean are similar to the advantages of a vaginal birth when there is no previous caesarean.
Babies born vaginally:
- Have lower rates of breathing difficulty than those born via caesarean, according to studies.
- Are exposed to beneficial bacteria during birth, which studies show are not available to babies born via caesarean.
- Are better at breastfeeding, according to 2021 research comparing 9,345 breastfed infants born vaginally or via caesarean
- Have lower rates of asthma, allergies and obesity in later life, according to emerging evidence
Mothers who have a vaginal birth:
- Recover more quickly, on average than those who have had caesarean; a major abdominal surgery (Source: NHS Caesarean recovery)
- Have better success initiating breastfeeding, compared with mothers having caesareans. Many studies show that caesareans "are associated with maternal/infant separation, reduced suckling ability, decreased infant receptivity, and insufficient milk supply".
- Are less likely to suffer from thrombosis (blood clots) according to various studies
A comprehensive review of 29,928,274 births, in 2018 found that pregnancies after caesareans are associated with:
- Increased risk of miscarriage
- Higher risk of stillbirth
- Increased risk of placenta previa (the placenta covers some or all of the cervix)
- Higher risk of placenta accreta (where the placenta embeds too deeply into the uterus, sometimes in a previous scar)
- Increased risk of placental abruption (the placenta comes away from the uterine wall)
These risks increase further with the more caesareans a woman has. However, these risks are all small and are, of course, outweighed by the needs of a baby and mother when emergency caesareans are required.
Is VBAC safer than repeat caesareans?
Whether or not VBAC is safer than repeat caesareans depends on your definition of "safer" and your point of view. For the majority of women, it's arguably a better option to have a VBAC than a caesarean. This is because the recovery time is shorter and easier for most who have an uncomplicated VBAC after c section.
Other factors that affect the comparison of safety:
- Your desire for more children. Repeat caesareans affect your womb as scars cause adhesions (scar tissue) to form. These adhesions can cause your placenta to form abnormally, creating additional risks in pregnancy.
- A VBAC avoids all the risks of surgery, including infection (internal, and of the scar).
- Babies usually fare better after vaginal delivery than c-section: studies show fewer babies born vaginally need help breathing than those born via caesarean.
What are the risks of VBAC?
- Tearing of the vaginal area
- Need for emergency caesarean (25% of vaginal deliveries in the UK)
- Pelvic floor injuries
- Urinary incontinence
- Need for an assisted delivery (using metal spoons called forceps or a suction cup, known as a ventouse) - according to RCOG this is 1 in 8 births.
- The risk of episiotomy (cut to the vaginal area) to help the baby be delivered
Sources: 2018, major review of 29,928,27 births.
Risks of VBAC in pregnancy are broadly similar to the risk of vaginal birth, with the additional (small) risk of uterine rupture, as covered in the safety section above. The risk of uterine rupture, according to RCOG, is 1 in 200 (0.5%).
Uterine rupture
VBAC in pregnancy comes with a small risk of uterine rupture. This can be fatal for mum, baby or both. Uterine rupture causing death in either baby or mother is a very rare event, according to UK studies.
The UK Obstetric Surveillance System's study of found uterine rupture occurred in just 0.2% of births.
"Uterine rupture is a severe but thankfully very rare complication. We found that many of the hospital maternity units across the country don't even see one case a year," - Professor Marian Knight of the National Perinatal Epidemiology Unit at Oxford University
In most cases of uterine rupture, it is identified early and both mother and baby are fine, after some medical support. NHS Consultant in Obstetrics and Gynaecology, Dr Abassi told us, "Uterine rupture, when it happens, is very dangerous. However, your healthcare team will monitor you and your baby very closely during a VBAC, to look for any signs of rupture."
Studies show uterine rupture can happen in first time mums with no history of caesarean, as well as non-pregnant women.
Risk of uterine rupture
The risk of uterine rupture, according to RCOG, is 1 in 200 (0.5 per cent). RCOG also say the "absolute risk of birth-related perinatal death [of mother and/or baby]" associated with vaginal birth after caesarean is "extremely low [and] comparable to the risk for [first-time mums] in labour".
RCOG's Guidelines for vaginal birth after caesarean also say having had a previous vaginal delivery is also "associated with a reduced risk of uterine rupture".
Studies show that the risk of uterine rupture increases:
- Each time a woman has another caesarean
- If labour is induced
- If there is a short interval between birth and the next pregnancy
Factors affecting VBAC success
RCOG say you are more likely to achieve a vaginal birth after caesarean if you:
- Have a healthy BMI (high BMI can reduce your chances)
- Already gave birth to at least one baby vaginally ("the single best predictor of successful VBAC")
- Had a planned caesarean
- Previously had a caesarean because of the baby's unfavourable position (not head down - breech - or transverse: sideways)
- Have a single, previous lower segment caesarean scar (not a "t" or "j", vertical or "classical" shaped scar)
- Have reached term (37 weeks)
- Present with a head-down (cephalic) baby
VBAC after two caesareans (VBA2C)
If you have had two or more Caesarean sections previously, you are likely to still be able to have a VBAC.
You will need to discuss your chances of success with your obstetrician. They should look at your individual factors, your history and any other health considerations to help you make an informed decision.
Royal College of Obstetricians and Gynaecologists say:
"[Studies show] there was no significant difference in the rates of uterine rupture in VBAC with two or more previous caesarean births [...] compared with a single previous caesarean birth."
"Women with two previous caesarean deliveries who are considering VBAC should be counselled about the success rate (71.1%), the uterine rupture rate (1.36%) and the comparable maternal morbidity to the repeat caesarean delivery option."
Why you shouldn’t have a VBAC?
Firstly, you shouldn't have a VBAC if you don't want one. If you feel you cannot have a VBAC for any reason, including anxiety and trauma, then you should not feel you should. It's acceptable to opt for a planned caesarean whether you have had a previous c-section or not.
Remember: you have the right to request a caesarean, according to NICE guidelines.
There are a few factors which would make vaginal birth after caesarean inadvisable, or very dangerous:
- Placenta previa (where the placenta covers the cervix partially or entirely)
- Previous uterine surgery (unrelated to caesarean)
- Historical caesarean scar which is not lower segment ("t", "j", "classical" or vertical caesarean scar)
- Previous uterine rupture
- Macrosomia (very large baby)
If these factors apply to you, discuss everything with your healthcare to fully understand your risks.
Source: RCOG guidelines for VBAC
VBAC induction
In the majority of cases, induction is not advised if you are attempting vaginal birth after a caesarean.
According to the RCOG guidelines on VBAC, there is an increased chance of uterine rupture in drug-induced VBAC (2-3-fold increased risk). Drug-induced labour is done using synthetic hormones given vaginally (via a pessary) or intravenously (via a drip).
In some cases, you can be induced using "mechanical methods". These include:
- Amniotomy (or artificial rupture of membranes) - where your waters are broken by a doctor
- Foley catheter (also known as a cervical balloon) is a method to dilate your cervix
RCOG says mechanical induction is associated with a lower risk of scar rupture and emergency caesarean.
However, all the risks and benefits of induction for VBAC will be discussed with you and every case is different. You should talk about all your decisions with your family, friends and your healthcare team to help you make any decisions.
VBAC criteria - who is eligible?
According to the Royal College of Obstetrician and Gynaecologists (RCOG) guidelines for vaginal birth after caesarean, most women are eligible to try.
UK RCOG Guidelines, VBAC - "There is a consensus (National Institute for Health and Care Excellence [NICE], Royal College of Obstetricians and Gynaecologists [RCOG], American College of Obstetricians and Gynecologists [ACOG]/ National Institutes of Health [NIH]) that planned VBAC is a clinically safe choice for the majority of women with a single previous lower segment caesarean delivery"
Mental health support after a traumatic birth
Further support for birth trauma is available from the Birth Trauma Association.
You should also be able to seek help with perinatal mental health from your midwife. You could also enquire about whether your hospital offers a "Birth Reflections" or "debriefing" session, to examine what happened in your last birth.
Your GP can also advise if you feel you need additional help or medication. You can also usually self-refer for NHS psychological therapies.
Related video: How to ease stitches after birth
