VBAC POSSIBILITIES AND RISKS

May 15, 2020 /

Written by Caroline Meyer

Many women opt to try for a vaginal birth after having had a caesarean and for around 70% of these women, the vaginal birth is successful. This does often have a lot to do with why the previous birth was done by caesarean section. A VBAC can be a bit more tricky and extra monitoring would be required, but it can be done safely in most cases. Just because your previous birth was a C-section, this does not mean that your next cannot be a vaginal birth. You can discuss with your doctor if you want to attempt a vaginal birth after having delivered via C-section with your previous pregnancy. 

In the past, C-sections were performed via a “classical incision”, which was a vertical cup into the upper wall of the uterus.  This caused weakening of the uterus and a strong likelihood of tears during labour. This led to doctors recommending that all births after a C-section be done the same way to reduce the risk of the uterus tearing during labour.  Since 1950, almost all caesareans are done by an incision across the lower abdomen and into the lower section of the uterus.  This is far less risky and has a reduced rate of complications should a vaginal birth be attempted after having had a caesarean.  Even if the external cut is a vertical one, the internal incision may be horizontal across the lower uterus and therefore pose lower risk. It is important to understand the type of incision done into the uterus and also the reasons why a caesarean was required previously. 

Some of the reasons a caesarean section may be required include: 

  • Placenta Praevia: This is where the birth canal is blocked by the placenta. 
  • Abnormal positioning: The baby may be presenting in a position which makes vaginal birth difficult or impossible such as feet first (footling breech) or across the uterus (transverse). 
  • Uterine Scarring: Scarring in the upper portion of the uterus due to previous surgery can increase the risk of uterine tears during labour, making a C-section a safer alternative. 
  • Illness: Mother or baby are too unwell to undergo the stress of vaginal birth and a C-section is the only alternative. 
  • Baby in Distress: If labour is not progressing safely and baby is showing signs of distress, a C-section may be indicated as the less risky option. 
  • Baby position: A lack of progress due to baby being in an unusual position may not always require a caesarean, but one may be done in some cases. 
  • Baby too large:  A normal baby would not often be too large to move down the birth canal, but there are rare cases where this occurs and a C-section would be recommended. 
  • Maternal anxiety: Some mothers will choose to have an elective caesarean due to anxiety or a belief that a C-section is safer. A previous stressful labour may make them feel that they are not able to have a successful vaginal birth in the future. 

A VBAC is usually fine for most women who want to attempt it but it is contra-indicated in a few circumstances. These would include issues such as the baby lying transverse, placenta previa, previous upper uterine incisions or scarring or previous vaginal birth attempts which resulted in tearing of the uterus.  Severe medical conditions or illness would also result in a VBAC being much riskier than a C-section. If labour is induced but the cervix does not soften enough then a caesarean may also be recommended by your health practitioner. 

Some of the benefits of VBAC include less likelihood of respiratory issues afterbirth and being able to cuddle and breastfeed your baby shortly after birth. This improves the chances of successful breastfeeding. There is less recovery time and less pain from a vaginal birth than a C-section and you are likely to spend a lot less time in hospital. Research shows a higher level of satisfaction after a vaginal birth and the hormone levels after birth are a lot higher as well. Less chance of complications such as infection and bleeding as well as less risk in future pregnancies of ectopic pregnancies or placental problems. You can drive or pick up a toddler within a day or two of a vaginal birth, whereas a C-section requires at least 4 to 6 weeks of recovery time. 

The risks of VBAC include a slight risk of the previous C-section scar pulling apart or rupturing during labour (less than 0.03%). Constant motoring is usually indicated so that this risk is mitigated. If this or other problems arise, there is a risk of having to undergo an emergency C-section. Furthermore, there may be a call for instrumental assistance using a vacuum extraction method or forceps. This can result in an increases risk of developing incontinence.  There is also a higher risk of an episiotomy in assisted births. 

It is important to develop a good relationship with your care providers and discuss options with them for the birth of your baby.  While some women prefer to attempt a VBAC, it is equally valid to request an elective Caesarean. Ask your doctor or midwife what the risk factors are in your particular instance so you can make an informed decision and mitigate risks to you and your unborn child.