Vaginal Birth After Caesarean (VBAC)
Vaginal Birth after Caesarean (VBAC) is the term used when a woman gives birth vaginally, having had a caesarean birth in the past. Vaginal birth includes birth assisted by forceps or ventouse.
Advantages of a successful VBAC
The advantages of a successful VBAC include:
- a vaginal birth (which might include an assisted birth)
- a greater chance of an uncomplicated normal birth in future pregnancies
- a shorter recovery and a shorter stay in hospital
- less abdominal pain after birth
- avoiding surgery
- easier breast feeding
Having a successful VBAC
Overall, about three out of four women (75%) with a straightforward pregnancy who go into labour give birth vaginally following one caesarean birth.
If you have had a vaginal birth, either before or after your caesarean birth, about nine out of ten women (90%) have a vaginal birth.
Most women with two previous caesarean births will have their next baby by caesarean.
A number of factors (risk factors) make the chance of a successful vaginal birth less likely. These are when you:
- have never had a vaginal birth
- did not make progress in labour and needed a caesarean birth (usually owing to the position of your baby)
- are overweight – a body mass index (BMI) over 30 at booking.
Disadvantages of VBAC
The disadvantages of VBAC include:
Emergency caesarean birth - there is a 25% chance that you will need to have an emergency caesarean birth during your labour which is only a slightly higher chance than if you were a first time mum in labour. This will be discussed with you.
Blood transfusion and infection in the uterus - women choosing VBAC have a 1 in 100 (1%) higher chance of needing a blood transfusion or having an infection in the uterus compared with women who choose a planned caesarean birth.
Scar weakening or scar rupture - there is a chance that the scar on your uterus (womb) will weaken and open. If the scar opens completely (scar rupture) this may have serious consequences for you and your baby. This only occurs in two to eight women in 1000 (about 0.5%). Being induced increases the chance of this happening (8-24 women in 1000 depending on the method used). If there are signs of these complications, your baby will be delivered by emergency caesarean.
Risks to your baby - the risk of your baby dying if you undergo VBAC is very small (two in 1000 women or 0.2%). This is no higher than if you were labouring for the first time, but it is higher than if you have an elective repeat caesarean birth (nine in 10,000 or 0.09%). However, this has to be balanced against the risks to you if you have a caesarean birth.
When VBAC not advisable
There are very few occasions when VBAC is not advisable and an Elective Repeat Caesarean Birth is a safer choice. These are when:
- you have had more than two previous caesarean births
- the uterus has ruptured during a previous labour
- you have a high uterine incision (classical caesarean)
- you have other pregnancy complications that require a caesarean birth such as a breech presentation
Going into labour when a VBAC was planned
You will be advised to labour in hospital so that an emergency caesarean birth can be carried out if it becomes necessary. There should also be facilities for immediate blood transfusion and neonatal resuscitation if required. These are the reasons why a home birth or birth centre birth are not recommended for a woman planning a VBAC. Contact the hospital as soon as you think you have gone into labour or if your waters break.
Once you are in labour, your baby’s heartbeat should be monitored continuously as a change in the heart beat can be the first sign of scar rupture. You can have an epidural if you choose.
You can opt to have a pool birth (if available) on Central Delivery Suite (CDS) with telemetry, which is wireless fetal heart monitoring enabling you to be more active in labour. Aromatherapy can also be offered, as well as pethidine and/or an epidural for pain management.
It will be recommended that you have a cannula (small plastic tube) inserted into your arm vein. This will be used if it becomes necessary to give you fluid or drugs in an emergency situation.
Not going into labour when a VBAC is planned
If labour does not start by 41 weeks, different options will be discussed with you by an obstetrician. These are:
- continue to wait for labour
- undergo a stretch and sweep procedure (stretching the cervix or entrance to the womb and sweeping the membranes in front of the baby’s head)
- induction of labour via artificial rupture of membranes (ARM) or insertion of a cook balloon
- repeat elective caesarean birth. Some women choose to aim for VBAC if they labour spontaneously but opt for a repeat elective caesarean birth rather than induction of labour at between 7-14 days past their due date.