VBAC is the acronym for "Vaginal Birth After Caesarean section".
Women who have had one previous uncomplicated lower segment caesarean section (LSCS) and no other adverse obstetric feature in the current pregnancy are suitable candidates for VBAC. Generally, the relevant factors to determine suitability for VBAC are as follows :
The chance of a successful VBAC is between 60% and 70%. It is generally higher for women who have had previous successful vaginal deliveries. The chance of success may be lower if the reason for the previous caesarean section was due to cephalopelvic disproportion (i.e. where the baby is relatively too big to pass through the maternal pelvis).
A successful vaginal birth is beneficial to the mother as it is generally associated with less bleeding, less blood transfusion, less infection, faster recovery with shorter hospital stay and less post-delivery pain and complications.
Successful VBAC has also no proven adverse effect on the baby. In terms of cost, a successful VBAC is cheaper than caeserean section birth.
The primary concern associated with VBAC is the risk of uterine rupture or tear. The incidence of uterine rupture is quoted as:
The risk of rupture may also increased in induction of labour.
Although it occurs rarely, uterine rupture can be life-threatening for both the mother and child. It may also result in the need for surgical removal of the womb (hysterectomy) for the mother as well as neurological impairment of the child (cerebral palsy).
In addition, if the trial of labour fails and the mother needs an emergency caesarean section, there may be higher risk of complications for the mother as compared to an elective or planned caesarean section or a successful VBAC. The costs of a failed VBAC would also be higher.
Before the decision for VBAC can be made, the obstetrician would:
Epidural is commonly used in labour to provide effective pain relief. It is safe and not associated with late detection of uterine rupture.
In addition, if trial of labour fails, epidural can be continued as a form of anaesthesia for emergency caesarean section to be carried out. Therefore, epidural can be chosen as a good form of pain relief while undergoing VBAC.
Apart from epidural, there are other options for pain relief such as breathing exercises, back massage, entonox gas, pethidine injection etc.
A decision for or against VBAC should be a joint decision between you and your obstetrician after having taken into consideration the pros and cons of VBAC in your situation.