Vaginal Birth after Caesarean (VBAC)
The term VBAC refers to having a vaginal birth when you’ve previously had at least one baby delivered by caesarean section. If your first baby was delivered by caesarean and you go on to have a subsequent pregnancy, you will need to decide how your next baby will be born. There are two options to choose from:
- elective repeat caesarean section (this is usually booked for the week leading up to your baby’s due date), and
Research indicates that women who choose VBAC tend to be less satisfied with their previous birth experience; want to have more control in their labour and birth; and tend to view caesarean section as the riskier option. Those who favour elective repeat caesarean section tend to be more focused on avoiding any repeat of their previous labour and birth experience; are less concerned about having more control; and view VBAC as the riskier option. Studies would seem to suggest that there are a number of factors which can influence women’s decision as to whether they opt for VBAC or elective repeat caesarean section. These include the woman’s personality, her feelings about her previous birth experience, and her own perceptions of risk.
Just because you have had a caesarean section with your last pregnancy, doesn’t mean that you will automatically have a caesarean birth next time. Indeed, research has found that where repeat caesarean sections are undertaken without there being a clinical indication (reason); this may not be of benefit to the mother and her baby.
Studies show that most women who decide to attempt VBAC will go on to achieve the vaginal birth that they wanted.
It used to be assumed that if you had a caesarean section for your first birth you would have a caesarean delivery in any future pregnancies. This is because in the past, it was routine practice to make a vertical incision (cut) down the centre of the uterus (womb) – called a ‘classical incision’. The concern was that this type of incision was associated with a risk of the scar from the previous caesarean tearing open during a subsequent labour – called uterine rupture. Uterine rupture is a life-threatening obstetric emergency which needs to be dealt with urgently.
However, caesarean incisions at ‘term’ (around the baby’s due date) are now routinely made horizontally in the lower part of the uterus (called a ‘Pfannenstiel incision’). This is also commonly referred to as a lower segment caesarean section (LSCS). Because the incision is made low down, along the ‘bikini line’, and the incision is made into the lower segment (section) of the uterus, the risk of uterine rupture is reduced and the health outcomes for mother and baby are much better. If, however, you require a caesarean section before 28 weeks of pregnancy, a classical incision is made because the uterus is still small and the lower segment has not yet formed.
Uterine rupture is now, thankfully, a rare occurrence which only affects around one in 200 women attempting VBAC.
Making an informed decision
Studies show that VBAC is safe for the majority of women who have had a previous lower segment caesarean section. However, VBAC usually takes place in a hospital Consultant-led unit because these facilities have the specialist equipment and services that might be needed ie operating theatres; on-site blood transfusion service; obstetric and anaesthetic staff; and a neonatal care unit. See also our article, ‘Choosing where to have your baby: place of birth’. There are a number of factors that will be taken into account when your midwife and doctor discuss future pregnancy options with you and how your baby will be born. These include:
- the reason(s) why you had your previous caesarean section
- your personal preferences, feelings and concerns
- the advantages and risks associated with having a repeat caesarean
- the risk of uterine rupture
- the health and wellbeing of you and your baby.
If your previous caesarean was performed because of an underlying medical condition eg cardiac (heart) disease, or because the shape of your pelvis meant a vaginal birth wasn’t possible; it is likely that you will need to have a caesarean section for each subsequent birth.
VBAC is considered an appropriate option for women who fall into the following categories:
- The woman has had a previous vaginal birth before having a caesarean section
- The previous caesarean was performed because the baby was a ‘breech presentation’ (bottom first). See also our article, ‘I’ve been told that my baby is ‘breech’!’ or because of placenta praevia (low-lying placenta)
- Studies show that women who have had a Trial of Labour (TOL) after a previous caesarean section for dystocia (failure to progress in labour), which was performed late in labour, are more likely to achieve a vaginal birth. NB. TOL is where a woman labours and her progress and the baby’s condition are closely monitored – should any concerns arise, a decision to proceed to a caesarean birth is made.
What are the advantages of VBAC?
Caesarean section is major abdominal surgery; therefore, where it can be avoided and women have a vaginal birth, they and their babies are likely to experience fewer side effects and enjoy a much quicker recovery. This includes less pain/discomfort post birth, a shorter hospital stay, feeling more able to care for a toddler and the newborn baby, and, if you felt disappointed or upset because your last baby was born by caesarean, you may also feel a greater sense of achievement and more positive birth experience. For more detailed information see our article, ‘Caesarean section’; ‘Recovering from your Caesarean birth’ and ‘Caring for yourself and feeling well after you have had your baby’.
What are the disadvantages of VBAC?
Research shows that the disadvantages associated with VBAC are similar, in the shorter term, to those often experienced following a vaginal birth ie pain/discomfort caused by perineal trauma, bruising and sutures (stitches) as well as, difficulty passing urine and stress incontinence (leaking urine). For more detailed information see our articles, ‘Healing ways’; ‘Severe perineal trauma: Third and Fourth degree tears’; ‘Caring for your bladder after childbirth’ and ‘Postnatal Exercises’.
Attempting VBAC instead of opting for a repeat elective caesarean section also carries a slightly higher risk of some more serious complications:
- Needing to have a blood transfusion
- Uterine infection (an infection in your womb)
- Uterine rupture.
These complications are not that common, but it is important that you are aware of all potential risks so that you are able to make an informed decision. Additionally, some women attempting VBAC will require assistance to birth their baby using forceps or the ventouse (vacuum extraction) – see also our article, ‘Forceps and Ventouse Births’. Around one quarter of women attempting VBAC will end up requiring an emergency caesarean section because of failure to progress in labour and/or fetal distress. Although there is an increased risk of complications with emergency caesarean sections compared to elective (planned) caesareans; a woman attempting VBAC is actually only at a slightly more increased risk of needing a caesarean than a woman who is labouring with her first baby!
What are the risks of having repeat caesarean sections?
Studies show that there are additional risks associated with having a repeat caesarean section. Although these risks are not that common, your doctor and midwife will still need to make you aware of them, so you can make an informed decision. They will also talk through the reason(s) why you had a caesarean section in your previous pregnancy and how these reasons might impact on this and any future pregnancies/births.
The risks specifically associated with having repeated caesarean births are as follows:
- An increased risk of haemorrhage (excessive blood loss) that needs to be treated with a blood transfusion – see also our article, ‘Anaemia after childbirth’
- Possible damage to the bladder – see also our article, ‘Caring for your bladder after childbirth’
- An increased risk of the baby becoming unwell/having breathing difficulties in the early postnatal period and needing to be transferred to a Neonatal Unit (NNU)
- An increased risk of the woman becoming ill during the weeks following the birth and needing to be readmitted to hospital
- The possibility that the woman might need a hysterectomy (removal of the uterus) if bleeding from the uterus cannot be controlled and becomes life threatening
- A slightly increased risk of the woman developing a serious illness that results in death.
Studies show that the risks associated with VBAC increase with the number of caesarean births that a woman has. This is why the decision about whether to go for a VBAC or a repeat elective caesarean section will need to include a woman’s plans for any future pregnancies.
How likely am I to achieve a successful VBAC?
When considering VBAC success rates for women who have had two or more previous caesareans, the available research is limited with conflicting findings. Some studies suggest that there is very little difference between those women achieving VBAC after one caesarean and those who have had two or more caesareans. However, other research has found that women who have had two or more previous caesarean births are less likely to achieve VBAC and that these births also carry greater risks. Nevertheless, your doctor will still discuss VBAC with you and you should not be discouraged from requesting VBAC.
Studies have shown that women who have had a previous preterm birth (where the baby was born early) are more likely to achieve a successful VBAC. However, where women go beyond their due date, there is an increased likelihood that they will not achieve VBAC. They should still be offered VBAC though! See also our article, ‘What happens when your baby is overdue?’
Women with a twin pregnancy can also achieve VBAC, although women having twins tend to be less likely to request this.
Are there any circumstances where I would be advised caution in attempting VBAC?
There are a number of factors that have been found to directly impact on women’s success in achieving VBAC. These will be discussed in more detail by your doctor and midwife, as relevant to your personal obstetric/medical history. They include the following:
- Women who need to have their labours induced or augmented with oxytocin are less likely to achieve VBAC
- Overweight women with a BMI > 30 at the start of pregnancy tend to be unsuccessful in achieving VBAC, although it is unclear why this is the case
- VBAC appears to be less successful in women having their first baby at 35 years’ of age or older
- VBAC success rates are lower in women whose previous baby became stuck during labour
- Women with pre-eclampsia (high blood pressure in pregnancy) are less likely to achieve VBAC.
What happens during a VBAC labour?
Only a small number of studies have focussed specifically on the labour care of women attempting VBAC. However, the actual content of labour and the birth of the baby in an uncomplicated trial of labour (where there is a history of prior caesarean section), is actually very similar to those women who haven’t had a previous caesarean. Care in a VBAC labour focuses on three main aspects:
- Caution when inducing labour; particularly, when the woman’s cervix is ‘unfavourable’ (not ready for labour)
- The use of oxytocin to augment labour (strengthen uterine contractions and speed up labour)
- Close surveillance of the woman and baby during labour for the rare occurrence of ruptured uterus. This includes being offered continuous electronic fetal heart rate monitoring to monitor your baby’s wellbeing and uterine contractions. Continuous fetal heart rate monitoring is recommended for all VBAC labours because changes to the baby’s heart rate and pattern can be an early indication of a possible problem with the scar. See also our article, ‘Monitoring your baby’s heart rate in labour’.
Pain relief (analgesia) in labour
You will be offered the same range of pain relief options during labour as women who have not had a previous caesarean section; including having an epidural. However, some women prefer not to have an epidural so that they are more aware of the early symptoms of uterine rupture – this includes abdominal pain that lasts between labour contractions. For more detailed information see our article, ‘Pain relief options for labour and birth’.
Some hospitals support women in using immersion in water for labour pain relief, but this varies between units. VBAC is classified as a higher-risk labour and birth, so some hospitals may discourage women from using the birth pool if it means their baby’s heart rate cannot be monitored continuously. Other units however, have specialist ‘waterproofed’ wireless fetal monitoring systems that can be safely used in water. For more detailed information see our article, ‘Waterbirth: Immersion in water for labour and/or your baby’s birth’
Can I have a VBAC at home?
Because VBAC is considered to be a higher risk labour and birth, your doctor will always advise you to deliver your baby in a hospital consultant-led unit. This is because continuous electronic fetal heart rate monitoring is recommended for VBAC, which can only be offered in hospital. Also, because, if the scar begins to tear and the uterus ruptures; the doctors can act swiftly to deliver your baby by emergency caesarean section. Emergency caesareans should be undertaken without delay to safeguard both the mothers and baby’s health and wellbeing. Where there is a delay because the woman needs to be transferred into hospital by ambulance, this can seriously compromise both the mother’s and baby’s health and safety. However, having a VBAC home birth is still an option and some women will choose this location for their baby’s birth because they feel a lot more relaxed and in control within familiar surroundings. If you feel strongly that a homebirth is what you want, we advise that you speak to a local Supervisor of Midwives who can talk through the various options to help ensure the safest outcomes for you and your baby. See also our article, ‘Support for parents: how supervisors of midwives can help’.
You might also wish to employ an Independent Midwife to provide your care.
Independent midwifery care
Independent midwives are fully qualified midwifery practitioners who are registered with the Nursing & Midwifery Council (NMC) and are self-employed. They do not work for the NHS and they charge a fee for the care and services that they provide. The majority of Independent midwives hold agreements with their local NHS Trust maternity services, so that the women in their care can be transferred into the hospital obstetric unit should any pregnancy or labour complications arise. Women advised against having a home birth because they are deemed to be ‘high-risk’, will often choose to employ an independent midwife because they will do their best to support the woman’s personal preferences. Many independent midwives are skilled and very experienced in providing a home birth service to women having a VBAC, women expecting twins, and those whose baby is lying in the breech position. Independent midwives can also provide the continuity of care during pregnancy, birth and during the initial weeks of motherhood, that NHS maternity services aren’t able to guarantee. Further information about the services that Independent Midwives provide and a list of midwives in your area is available at: independentmidwives.org.uk
Because there is a wealth of evidence that shows the negative effects associated with having a caesarean section compared with a vaginal birth, midwives and doctors will always try to ensure that caesarean sections are only undertaken when absolutely necessary. The above information provides you with an overview of VBAC; however, we would urge you to also talk things through in more detail with your own midwife and doctor who can support you in making the ‘right’ decision for you. It is also worth asking your midwife whether there is a VBAC clinic at your local hospital, where you can access additional support and information.