Vaginal birth after C-section (VBAC)

What is VBAC?

VBAC refers to vaginal birth after caesarean. 

What are the chances of successful VBAC after 1 C-section?

3 in 4 women with 1 previous C-section will have a successful vaginal delivery. This is particularly if they:

• Have had previous vaginal birth (either before or after their C-section)
• Had labour start naturally 
• Are not obese 

How do I know if I am suitable for a VBAC?

This depends on a few factors including:

• Why you had your previous C-section: chances of successful VBAC is higher if it was due to factors no longer present in your current pregnancy e.g. baby was breech (head up) or placenta was low-lying/previa versus if it was due to factors that can still happen in your current pregnancy e.g. your cervical dilation was stuck at 3cm

• Complications during your previous C-section: if the C-section was difficult and a vertical, inverted T or J-shaped cut was made on your uterus instead of the usual horizontal cut on your lower uterus, this puts you at higher risk of the scar giving way 

• Complications during your current pregnancy: you should not have factors that make you unsuitable for vaginal birth e.g. baby in transverse position (sideways) or placenta previa, severely small baby (fetal growth restriction) who is unable to tolerate labour stress 

Who is unsuitable for a VBAC?

• 2 or more previous caesarean sections
• Previous caesarean section had vertical or inverted T cut 
• Current pregnancy factors that make you unsuitable for vaginal delivery 

What are the pros and cons of VBAC versus elective repeat C-section (ERCS)?

If you have a successful VBAC, you will have a greater chance of achieving VBACs in your subsequent pregnancies. However, if your VBAC is unsuccessful, you will need an emergency C-section. 

The main concern of VBAC is scar rupture, which is where the previous C-section scar gives way either before or during labour, or after delivery. Although the risk is low, scar rupture can result in serious complications – baby’s oxygen supply can be cut off and he/she can end up with permanent brain damage, cerebral palsy or death, while mother can suffer from excessive blood loss. The risk of delivery-related death is 4-10 per 10 000.

Choosing ERCS means that you will no longer have another chance at VBAC if you are planning for more children. For uncomplicated pregnancies, ERCS is best done after 38 weeks of pregnancy. With every caesarean section, there may be more internal scarring and a higher risk of placenta of your next pregnancy sticking to the scar resulting in bleeding problems and possible hysterectomy (removal of uterus).