Vaginal birth after caesarean – VBAC

Many women choose Vaginal Birth after Caesarean, or VBAC, after a previous Caesarean section. Find out more about VBAC in New Zealand.

Many women have a Caesarean section and then have subsequent pregnancies. For a few women it is necessary to have a planned Caesarean section, but for many the decision about how to birth in the next pregnancy is not clear cut. In the majority of cases the reason for Caesarean section does not affect subsequent pregnancies and vaginal birth will be an option. This is called Vaginal Birth after Caesarean – or VBAC.

Why would I have a Vaginal Birth after Caesarean?

Many women assume that once they have had a Caesarean section it will always be necessary to have a Caesarean section thereafter. However, usually it is safe to labour and give birth vaginally after one previous Caesarean section, as the reason for Caesarean section will not necessarily be repeated. For example –

• Breech position in previous pregnancy, but baby is head down this pregnancy
• Baby was distressed in labour – fetal distress will not necessarily happen again
• Baby was facing mum’s front (face to pubes), making labour slow and difficult, but this pregnancy baby is tucked in and facing mum’s back
• Mother had pre-eclampsia in her previous pregnancy, which has not recurred
• Mother had a bleed in her previous pregnancy

There are other reasons which would indicate that a Vaginal Birth after Caesarean should be successful.

Occasionally the reason for Caesarean affects subsequent pregnancies, for example –

• Caesarean in early pregnancy involving a cut through the centre of the womb, making labour and birth dangerous
• The shape of the mother’s pelvis – although often this is a combination of head position, so will not always indicate that a Caesarean section needs to be repeated.

Generally, vaginal birth is safer for mother and baby and has a much quicker recovery time-

• Breastfeeding is easier following a vaginal birth
• Hospital stay is shorter
• Any further pregnancies are less likely to have complications
• There is also a lower risk of infection following the birth.

Where possible, women will be advised to have a vaginal birth following one Caesarean section.

When a woman has had 2 previous Caesarean section she is usually advised to have a Caesarean section thereafter – the womb will have increased scar tissue, which increases the risk of the muscle tearing. This is known as uterine rupture. All individual cases should be discussed with an obstetrician.

What does a Vaginal Birth after Caesarean involve?

Labour and birth after a previous Caesarean section will be just like a first birth, if the women never went into labour with the previous pregnancy. If the Caesarean section was carried out later through the previous labour then this labour may proceed like any other second or subsequent birth – generally quicker!

There is global advice that is given for vaginal birth after a Caesarean–

• Give birth in a unit with skilled midwives, doctors and obstetricians, where immediate Caesarean section is available
• Come to hospital early in the labour
• Once labour is established (regular, painful contractions) continuous monitoring of baby is advised. This is called a cardiotocograph, or CTG.
• A cannula – a plastic tube – is inserted into a vein in the arm in case a drip is needed in an emergency
• A blood sample is taken to check the women’s well being and to reserve a sample in case a transfusion match becomes necessary.

This is often referred to as ‘trial of labour’. Ask your maternity carers about the success rate of vaginal births after trial of labour at your local hospital– there are great variations in number of successful vaginal births after Caesarean, from 60-80%.

What pain relief will be available?

The same pain relief is available for VBAC as for any other labour.

Often women are encouraged to have an epidural, due to the increased risk of a Caesarean section. However, if a Caesarean section becomes necessary an epidural top-up would be necessary in order to ensure that the operation would not be painful, and this causes a time delay – so it is not necessary to have an epidural.

What are the risks and complications of Vaginal Birth after Caesarean?

The greatest risk of vaginal birth after Caesarean (or Cesarean) is that the uterus scar site will rupture during contractions, due to stress on the scar tissue. For this reason some maternity units do not offer syntocinon induction or augmentation (speeding up the labour) to women who have had a previous Caesarean section. For those units which do offer syntocinon in a trial of labour, the maximum recommended length of time is 6 hours.

This risk of uterine rupture is very low in women who have only had one previous Caesarean section, with a scar low in the womb – a lower section Caesarean section.

There is the risk that the labour will be unsuccessful, resulting in a Caesarean section anyway. Usually, however, the chances of a successful vaginal delivery are much higher, so it is crucial that you discuss your individual circumstances with your maternity professionals.

How can I increase my chances of a successful VBAC?

A successful labour is dependent on the passage of the baby through a tight passage – your birth canal. There is much we can do to increase the chance of a successful journey –

• Stay gently active in pregnancy – walking, swimming and carrying our normal chores. This increases your fitness for labour.
• Maintain a good posture in pregnancy to encourage the baby into a neat, tucked in position. This decreases the width of the baby’s head as it comes through the pelvis.
• Remain upright in labour. Do not let the CTG monitor restrict your movement and changes of position. It is possible to kneel on the bed, be on all fours, stand, lie on your side – and still keep a close eye on baby’s well being. Lying semi recumbrant on the bed gives baby an uphill journey!
• Remain positive – most women achieve a vaginal birth!

Will I need a Caesarean section?

Despite all their best efforts, approximately 30% of women still require a Caesarean section. If this is the case the procedure will be the same as for any other Caesarean section. Unless there is an emergency then every effort will be made to keep you awake and allow your partner into theatre to see the birth.

You will not have failed – you will have given it your best shot! And you will know you did everything possible. Make sure you are well looked after by whanau and friends as Caesarean section is a major operation and you also have children to care for.

Finally –

Ensure that you understand the risks and benefits of Vaginal Birth after a Caesarean, to enable you to make an informed choice.

The key messages from the NZ Guidelines Group state that one previous Caesarean section alone is not an indication for a further Caesarean section. If there are no other contraindications, women should be encouraged to labour spontaneously.

Useful articles

Click here to read more about epidural anaesthesia.

Sometimes a VBAC results in a Caesarean section. Visit our Kiwi Families articles on Caesarean section to find out more about the procedure.

For further information on the NZ Guidelines Group visit www.nzgg.org.nz.