Vaginal birth after caesarean section

Vaginal birth after (one) caesarean section (VBAC) (UK) or Trial of labour after caesarean section (TOLAC) is an option that many women may want to consider.

Here is some information regarding the same for women who want to make an informed choice.

If you have had a previous caesarean section for either breech presentation or on request without any obstetric indications, a VBAC may be considered, provided all parameters are normal this time round such as normal baby growth, no medical problems ( like gestational diabetes) etc.

If however, the caesarean section was done due to failure of the head to come down into the pelvis or failure of dilatation or opening of the cervix, the chances of a successful VBAC may be lesser.

I generally tend to counsel my pregnant “patients” once at first or booking visit and again on several occasions after 34 weeks.

The decision can be made together with the family involved.

If the choice of VBAC is made, the best possibility of a vaginal or natural birth would be if the labour pains start spontaneously. For this to happen, I may wait until about 3-5 days beyond the due date. Also, natural ways of inducing labour such as membrane sweeping and stretching of the cervix (neck of the womb) may help.

The important aspects to be understood when opting for VBAC are the following:

  1. Is the pregnancy going ok so far?
  2. Is the baby growing ok, not too big or small?
  3. Is the pelvis adequate for the size of the baby? Although, this is very subjective and not very accurate.
  4. Are the risks and benefits understood by the woman and her family?

The benefits of VBAC are that the recovery is faster, no cuts or wounds on the tummy and hence lesser pain (although a small cut called episiotomy may be needed on the skin between the vagina and back passage), no risk of major surgery and lesser risks in future pregnancies.

The cons to consider are- more intensive monitoring in labour with continuous cardiotocography

(CTG/NST) which is a kind of heart beat monitoring of the baby, need for pain relief by epidural analgesia (a small injection on the back to reach a space in the spine and a connection to a thin catheter through which medications to numb the pain are given), and need for a operation theatre and anaesthetist on standby in order to perform an emergency c-section if required.

The risks of a VBAC are scar rupture (opening up of the previous cut on the womb), need for emergency section if there is any sign of scar rupture, failure to progress normally or if there is sudden bleeding.

Although scar rupture is a very serious risk it is rare. It may be associated with danger of fetal death and internal bleeding and possible need for emergency hysterectomy (removal of uterus),

The risk of scar rupture with spontaneous labour pains is about 1 in 200 cases. This risk goes up if the labour is induced, which is why induction of labour in women with previous section is not generally recommended.

The option of elective repeat caesarean section ( planned caesarean section) is also to be discussed.

Dr. Aruna Muralidhar, MD, MRCOG ( UK), FICM

Senior consultant Obstetrician and Gynaecologist, Fortis La Femme, Richmond circle, Bangalore.