Explainer: vaginal birth after caesarean

We’ve come a long way from the first documented successful caesarean. In 1500, Jacob Nufer, a Swiss farmer who castrated pigs for a living, operated on his wife after a labour of several days involving 13 midwives. Both mother and baby not only survived but the woman went on to have five more vaginal births, with one involving twins.

These days nearly one in three pregnant women in Australia gives birth by caesarean. The most common type – lower segment caesarean section (LSCS) – involves an obstetrician making a horizontal cut along the lower part of the uterus. Sometimes, such as when the baby is very premature, the cut is made vertically through the uterus. This is known as a classical caesarean section.

Women planning their next birth after caesarean are faced with two options: they can have a repeat caesarean section when the baby is term (around 39 weeks), or they can attempt a vaginal birth after caesarean (known as a VBAC).

Risks and benefits

The advantages of a VBAC include a greater chance of an uncomplicated birth in future pregnancies, shorter recovery time, reduced risk of blood clots, and enhanced mother-infant bonding.

Women who have caesarean sections stay in hospital longer and are more likely to need re-admission for complications such as infection. Other aspects of mothering may be affected, such as picking up their baby or toddler, being able to drive a car and carrying the washing.

There is also emerging evidence that caesarean sections may have longer-term effects, such as increasing susceptibility to disease.

Disadvantages of VBAC include the risk of a uterine rupture. This is when the uterine wall opens up during the labour. It can be very slight, or extreme, where the uterus completely opens up. Uterine rupture occurs in about one in 200 VBACs and can be catastrophic for both mother and baby.

In some cases, when a woman seeks to have a VBAC she may end up having a caesarean section. If an emergency caesarean is required, she is at increased risk of blood loss.

In terms of the baby’s safety, guidelines on VBAC just released by the United Kingdom’s Royal College of Obstetricians and Gynaecologists (RCOG) state that the risk of a baby dying during labour and birth is extremely low and is similar to the risk for women having their first baby.

Reversing the declining trend

Most Australian women (84.4%) have a caesarean for subsequent births after a caesarean. Only 15.5% of women have a VBAC. In private hospitals, this rate is even lower, at 11%. Internationally, VBAC rates vary from 45-55% in Finland, Sweden and the Netherlands to 10% in the United States.

VBAC rates have declined internationally since 1999 when the American College of Obstetricians and Gynecologists (ACOG) changed its VBAC guidelines. Only facilities that had immediate access to an operating theatre, rather than “within a reasonable time frame”, were recommended to offer VBAC.

The ripple effect of this decision led to VBAC no longer being offered in many smaller hospitals and birthing centres, and the popularity of elective caesarean increased. This also impacted on countries such as Australia, where the VBAC rate was once around 60%.

More recent ACOG guidelines recognise the restrictive aspect of the term “immediate access” and suggest VBACs can occur in other settings as long as logistical emergency plans are in place.

However, it’s hard to change an established culture and it will take time.

What drives women’s decisions?

We have been investigating what motivates women to chose VBAC or repeat caesarean section.

In one study, we found belief systems fell within a broader motherbirth or childbirth paradigm. On the “motherbirth” side, the mother’s physical health and emotional well-being were seen as important, in order for her to care for her baby. These women were more likely to choose a VBAC.

On the “childbirth” side, the mother put the needs of the baby above her own needs and took a more sacrificial perspective, seeing this as what a “good mother” would do. These women were more likely to choose a repeat caesarean section.

More recently, we explored the rising trend of women seeking a homebirth after caesarean section in Australia. While a small percentage (0.4%) of women in Australia choose the option of a homebirth, more appear to be doing so after a previous caesarean (also known as a HBAC) than previously.

In our in-depth interviews, women explained they didn’t want a repeat caesarean, often because their previous experience was traumatic. Women gave accounts of bullying and intimidation from health care professionals and recounted labour interventions negatively.

Lack of support for VBAC from health professionals, strict policies and procedures, and fear-based obstetric practice can be a source of distress and confusion for women, forcing some to make the choice to avoid hospital altogether.

Vaginal birth or caesarean?

There are times when a VBAC would not be recommended, such as when a classical caesarean section had occurred. But the majority of women who experience a previous caesarean section are able to have a VBAC.

More than 70% of VBACs are successful, meaning an emergency caesarean was not required. Factors that contribute to a successful VBAC include going into spontaneous labour (rather than being induced), having a previous vaginal birth (prior to caesarean) or VBAC and having a low-risk pregnancy (so, no diabetes, high blood pressure, obesity and so on).

A recent European paper looked at health professionals' attitudes and beliefs about VBAC in countries where half of births after caesareans were vaginal. These clinicians (and all members of the care team) had a positive and confident attitude about VBAC and recognised the benefits of VBAC for women, including feeling empowered.

Locally, New South Wales Health identified VBAC as a target area in its Towards Normal Birth policy in 2010. NSW Health has since published a VBAC policy for clinicians and a consumer brochure to ensure women are being given the right information and to help increase the VBAC rate.

When it comes to childbirth, and whether to have a VBAC or repeat caesarean, women need balanced, evidenced-based information. And they need their choices supported.

Hannah Dahlen is affiliated with the Australian College of Midwives. She receives funding from the NHMRC and ARC

Hazel Keedle does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.