Information for women considering Vaginal birth after a caesarean section (VBAC)

In the developed world, approximately one in four women will have a caesarean section for various reasons. If the reason, for which a caesarean section was preformed in the last pregnancy is not present in the current pregnancy, many women do choose to have a vaginal birth. This is commonly referred to as VBAC (vaginal birth after caesarean). With good obstetric care, about 50% of all women attempting VBAC will be able to deliver vaginally. The most common reasons women fail to achieve a VBAC is usually slow progress or failure to progress, particularly as medication to increase uterine activity (oxytocics) are not usually given with VBAC due to associated risks.

 

Your suitability for VBAC

This issues may need to be discussed several times as the pregnancy progresses.  There may be emerging information which can make you more suitable or unsuitable for a VBAC.  The following may indicate unsuitability:

• Lack of motivation, being unsure, fear of failure.
• Previous classical (up and down) or inverted (T-shape) scar.  You would have been told about this at the time of your previous C-section if this was the case and your previous medical notes should also indicate if this was the case.
• Previous uterine rupture.
• If your cervix is unfavourable.  The chemical agent used to ripen the cervix (prostaglandins) is contra-indicated if you have a uterine scare.
• Recurring conditions (i.e. small pelvis, significant medical conditions)
• Foetal conditions in the pregnancy, (i.e. low placenta, transverse position of baby)
• Any other conditions or situations which after discussed both of us find unsuitable for VBAC.

 

Advantages of VBAC

Many women feel a sense of achievement after a vaginal birth, particularly so if a previous caesarean section was unexpected, some women may consider it a failure.

Advantages:

• You will take less time to recover with a shorter hospital stay.
• You are less likely to need further surgery, or need a hysterectomy or be admitted to an  Intensive Care Unit.
• You are less likely to develop a blood clot (deep vein thrombosis or pulmonary embolism).
• You are less likely to have a placenta preavia and other placenta related complications (i.e. low placenta and adhered placenta) in future pregnancies.
• you are less likely to need a blood transfusion.
• If successful this time, you can have a vaginal birth in a future pregnancy.  (However, if you have had two caesareans, most obstetricians would not recommend vaginal birth).

 

Disadvantages/risks of attempting and/or having a VBAC

Besides the disadvantages of vaginal birth in general, (i.e. pelvic floor damage and increased incidence of incontinence and prolapse) you should consider the following:

• How would you feel if your VBAC fails?  Particularly if you have an emergency caesarean section after a trial.
• There is an increased risk of uterine rupture particularly in labour, with life threatening consequences for mothers (may need a hysterectomy) and baby (foetal distress and still-born).  Fortunately with excellent obstetric care, the incidence is low (less than one out of 100 women having VBAC).  The signs of uterine rupture are difficult to detect and you would have continuous monitoring in labour.  Any signs of indicative of rupture will require urgent delivery.

 

Your individual chances of achieving a VBAC

• Chances are higher if you have delivered at least one baby vaginally in the past.
• Chances are higher if your previous C-Section was for breech.
• Chances are higher if you had a spontaneous labour.

 

Management of VBAC

• Labour will be managed as high-risk labour.
• IV access and blood will be taken for blood count and group, and held in case a transfusion is required.
• Continuous foetal heart monitoring and close monitoring of progress.
• Regional anaesthesia is not contraindicated.