Giving birth via a VBAC? The benefits and risks.

A VBAC is a "vaginal birth after caesarean section".


The National Institute for Health and Care Excellence (NICE), Royal College of Obsteticians and Gynaecologists (RCOG) and the American College of Obstetricians and Gynaecologist (ACOG) have unitedly come to the consensus that a VBAC is a safe choice for the majority of women versus a ERCS, an "elective repeat caesarean section" where you choose to have a planned caesarean.



But what information is available to help you make an informed choice?


All women who have had a previous c-section should be offered a VBAC if their singleton baby is in an optimal head-down position (cephalic presentation) at 37 weeks for a vaginal birth.


A planned VBAC is contraindicated is you have previous experienced a uterine scar rupture where a previous c-section scar or uterine scar from other surgery has ruptured. A VBAC is also contraindicated if your previous c-section was via a vertical incision (a classical c-section) or if you have placenta previa (major, but also in some cases minor placenta previa is a contraindication too) or placenta accreta where the placenta grows too deeply within the uterine wall. Major placenta previa is when the placenta totally blocks the cervix.


VBAC - The benefits.

  • A successful VBAC has the fewest complications compared to a ERCS.

  • The chance of a successful VBAC is 72-75%.

  • If you've had a vaginal delivery previously as well as a previous c-section, the success rate of a VBAC increases to 85-90%.

  • A successful VBAC increases the likelihood of future vaginal births.

  • A successful vaginal delivery means you can be discharged home earlier.

  • The risk of birth-related perinatal death associated with VBAC is extremely low and is comparable to a women giving birth vaginally to their first baby.

  • Women should be advised that a planned VBAC should be conducted in a staffed and equipped delivery suite to allow for continuous monitoring of your baby as soon as regular contractions are established.


VBAC - The risks.

  • A VBAC is associated with a 1 in 200 (0.5%) risk of uterine rupture - a maternal age of 40 years +, obesity (BMI over 30) and a short inter-delivery interval (less than 12 months since last delivery) are linked to this risk.

  • An unsuccessful VBAC will lead to delivery via an emergency caesarean.

  • If you labour needs to be induced (started) or augmented (speeded up) there is a 2-3 fold increased risk of uterine rupture and around a 1.5 fold increased risk of caesarean.

  • In 8 out of 10,000 women, damage to the baby's brain occurs because oxygen damage during planned VBAC, but this is a similar risk for women during their first labour. For ERCS this figure is 1 out of 10,000.

  • 2 in 100 women will required blood transfusion because of bleeding (compared to 1 in 100 after ERCS).


ERCS - The benefits.

  • A planned ERCS reduces the chance of having an emergency caesarean following an unsuccessful VBAC.

  • Some women may opt straight away for a ERCS, due to the emotional trauma experienced in a previous unplanned/emergency caesarean delivery and would like the control of a planned repeat caesarean.


ERCS - The risks.

  • Having a ERCS is associated with a small increase risk of placenta previa and /or accreta in future pregnancies,

  • Women will require a longer hospital stay and the recovery period will be longer.

  • Having an ERCS (which should be conducted after 39 weeks gestation) leads to longer recovery and the future deliveries will likely lead to caesarean delivery due to increases risk of placenta previa/accreta.

  • There is an increase risk of maternal death (13 in 100,000 for ERCS compared to 4 in 100,000 for VBAC).

  • Your next baby will likely be delivered via a third caesarean.

  • In a future pregnancy, your placenta may implant over your scar site causing a low-lying placenta, increasing the risk of bleeding during pregnancy, premature labour and heavy bleeding during the caesarean.

  • There is an increased risk of placenta accreta in future pregnancies (where the placenta grows too deeply in the uterus wall) increasing the risk of needing a hysterectomy after delivery.