Open a PDF version to print this topic

HealthInfo Canterbury

Birth after caesarean section

The best available evidence shows vaginal birth is a safe choice for most women who have previously had a caesarean.

What are my choices for birth after a caesarean section?

BirthAbout one in every four or five women in New Zealand gives birth by caesarean (a surgical operation where a cut is made in your abdomen and your baby is born through that cut).

If you have had one or more caesareans, you may be thinking about how to give birth next time. Whether you choose to have a vaginal birth or a caesarean in a future pregnancy, either choice is safe with different risks and benefits.

In considering your choices, your obstetrician will ask you about your medical history and your previous pregnancies. They will want to know:

You, your lead maternity carer (LMC), and specialist obstetrician, will consider your personal wishes and future fertility plans when making a decision about vaginal birth or caesarean section.

What is trial of labour (TOL)?

It is a planned attempt to birth vaginally when a woman has had a previous caesarean section.

What is VBAC?

VBAC stands for "vaginal birth after caesarean". It is the term used when a woman gives birth vaginally, having had a caesarean in the past.

Vaginal birth includes birth assisted by forceps or ventouse.

What is an elective repeat caesarean?

An elective caesarean means a planned caesarean. The date is usually planned in advance at your hospital antenatal visit.

The caesarean usually happens in the seven days before your due date, unless there is a clinical reason to do this at a different time.

Christchurch Women's Hospital does not perform sterilisation at the time of caesarean section, as the failure rate is much higher than with other forms of contraception.

What are the advantages of a VBAC?

Birth after Caesarian Section Picture2The advantages of a VBAC include:

When is VBAC likely to be achieved?

Overall, about three out of four women (75%) with a straightforward pregnancy, who go into labour, give birth vaginally following one caesarean.

If you have previously had a vaginal birth, either before or after your caesarean, about nine out of 10 women (90%) who go into labour have a successful vaginal birth after caesarean.

Some women with two previous caesareans will choose to have their next baby by caesarean. However, should you go into labour, your chance of a successful vaginal birth is between 70% and 75% (three out of four women).

What are my chances of a VBAC?

A number of factors (risk factors) make the chance of a vaginal birth less likely. These are when you:

What are the potential disadvantages of trial of labour (TOL)?

Emergency caesarean

There is a chance you will need an emergency caesarean. This happens to about one in four women (25%). This is only slightly higher than if you were labouring for the first time, when the chance of an emergency caesarean is one in five women (20%). The common reasons for an emergency caesarean are labour slowing or if there is a concern for the well-being of you or your baby.

Blood transfusion and infection in the uterus

Women choosing TOL have a one 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.

Scar weakening or scar rupture

There is a very small chance that the scar on your uterus will weaken and open prior to birth – this occurs only in two to eight women in 1000 (about 0.5%). If the scar opens completely (scar rupture) this can have serious consequences for you and your baby. Being induced can increase the chance of this happening. If there are signs of these complications, your baby will be delivered by emergency caesarean.

Risks to your baby

The neonatal and perinatal mortality risk if you undergo TOL is very small (two in 1000 women or 0.2%). This is the same as if you were labouring for the first time, but it is higher than if you have an elective repeat caesarean (one in 1000 or 0.1%). However, this has to be balanced against the risks to you if you have a caesarean (see below).

These disadvantages are more likely in women who attempt TOL and end up requiring a caesarean.

When is TOL not advisable?

Birth after Caesarian Section Picture 3There are very few occasions when TOL is not advisable and repeat caesarean is a safer choice. These include:

What are the potential advantages of elective repeat caesarean?

The advantages of elective repeat caesarean include:

What are the disadvantages of elective repeat caesarean?

All serious risks increase with every caesarean you have

More scar tissue occurs with each caesarean. This increases the possibility of the placenta being low lying (placenta praevia) or growing into the scar making it difficult to remove at caesarean (placenta accreta or percreta). This can result in heavy bleeding, blood transfusion and you may require a hysterectomy.

There are several disadvantages of elective repeat caesarean.

A longer and possibly more difficult operation

A repeat caesarean usually takes longer than the first operation because of scar tissue. Scar tissue may also make the operation more difficult and can result in damage to the bowel or bladder. There are rare reports of accidental cuts to the baby at caesarean.

Chance of a blood clot (thrombosis)

A blood clot that occurs in the lung is called a pulmonary embolism. A pulmonary embolism can be life-threatening (death occurs in less than one in 1000 caesarean deliveries).

A longer recovery period

You may need extra help at home and will be unable to drive for about six weeks after birth (check with your insurance company).

Breathing problems for your baby

Breathing problems are quite common after caesarean and usually do not last long. Occasionally, the baby will need to go to the Neonatal Intensive Care Unit (NICU) as between three and four in 100 babies (3 to 4%) born by planned caesarean have breathing problems compared with two to three in 100 (2 to 3%) following VBAC. Waiting until seven days before the due date minimises this problem.

What happens when I go into labour when I'm planning TOL?

When you think you are in labour, or if your waters have broken, contact your LMC for advice. Your LMC may arrange to meet you at your home or at the hospital to assess what is happening.

Once labour is established, you and your baby will be monitored closely (wireless monitoring is available, so you can move around freely). You can have an epidural for pain relief if you choose.

We advise that you plan your birth at the hospital, so that there are the necessary facilities for both you and your baby in the event that a caesarean is required.

What happens if I do not go into labour when planning TOL?

Birth after Caesarian Section Picture 4If labour does not start by 41 weeks, different options will be discussed as part of a three-way discussion with you, your LMC, and specialist obstetrician at the clinic. These are:

What happens if I have an elective caesarean planned and I go into labour?

This occurs in 10% of women.

Telephone your LMC to let them know what is happening. It is likely that a caesarean will be performed, when it is safe to do so, if labour is confirmed. If labour is very advanced, or if the labour is early (before 37 weeks), then TOL may be more suitable. The obstetrician from birthing suite will discuss this with you.

Written by Maternity Outpatients Department, Christchurch Women's Hospital. Adapted by HealthInfo clinical advisers. July 2013.


Page reference: 68106

Review key: HIBCS-65966