[CG] VBAC vaginal birth after caesarean section


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Pregnancy and childbirth following Caesarean Section:

The decision about mode of birth should consider:

  • Maternal preferences and priorities.
  • The woman’s past obstetric history.
  • General discussion of the overall risks and benefits of Vaginal Birth after Caesarean Section (VBAC) and Elective Repeat Caesarean Section (ERCS).
  • All women suitable for VBAC should be offered this option

Women who want VBAC should be supported and:                                

  • Be informed that women who labour spontaneously with a previous section but without a previous vaginal birth have a 72-75% chance of a vaginal birth.
  • Be informed that women who labour spontaneously with both previous CS and a previous vaginal birth are more likely to give birth vaginally with an 85-90% chance of success.
  • Be informed that uterine rupture is very rare but increased with VBAC: about 1 per 10,000 repeat CS and 50 per 10,000 (1 in 200) VBAC.
  • Be informed that intrapartum infant death is rare (about 10 per 10,000 – the same as the risk for women in their first pregnancy), but increased compared with planned repeat CS (about 1 per 10,000).
  • Be advised to have electronic fetal monitoring during labour: indicating this is unit policy if VBAC attempted.
  • Should labour in a unit where there is immediate access to CS and on-site blood transfusion.
  • If having induction of labour should be aware of the increased risk of uterine rupture (80 per 10,000) if mechanical methods (amniotomy or Foley’s catheter) are used compared to 240 per 10,000 if prostaglandins are used).

Management of VBAC


  • An individualized risk assessment should be made for each woman and full documentation of delivery plan made in the notes.
  • Previous notes should be reviewed. If not available or the woman delivered in another unit then information regarding her previous deliveries should be sought early in the antenatal period.
  • Consultant input during the antenatal period should be offered / arranged.
  • The woman should be given the current RCOG Patient Leaflet on VBAC and the GGC Elective Caesarean Section leaflet early in her antenatal care and invited to return with any questions at a subsequent clinic appointment.
  • Consultant opinion should be sought regarding their preferences about IOL in VBAC cases BEFORE discussion with woman. Ideally, any woman considering IOL after a previous Caesarean Section should be reviewed by their consultant. She is entitled to seek a second opinion.
  • Women who have had two or more caesarean sections should be counselled by a senior obstetrician. This counselling should include detailed risks of uterine rupture and maternal morbidity. We would not usually offer these women IOL.
  • A plan should be documented in the casenotes by 34 weeks at the latest.
  • Complete and sign the Birth after Caesarean (VBAC vs ERCS) form (Appendix 1)

When is Elective Repeat Caesarean Section the optimal choice?

  • Offer elective CS to all classical UTERINE scars, ”T” or inverted “T” incisions and extensions of uterine scars that have a vertical component (i.e. not “lateral LUS extensions”).
  • Offer CS to women from overseas with vertical midline abdominal scars and who cannot be sure that they had a transverse lower segment uterine incision.
  • Offer CS to women who have absolute contraindications such as placenta praevia.
  • Consider factors that may increase the risk of uterine rupture – short inter-delivery interval (<12 months), post-date pregnancy, maternal age >40, obesity, macrosomia, twins.

Later antenatal care

  • Check that ultrasound localisation of placental site has been performed by 32 weeks.
  • Record Plan in notes PRIOR to Admission: document DATE and agreement of Consultant. Discuss VBAC again to ensure no new issues.
  • Await spontaneous labour and advise woman to contact Maternity Assessment Unit when she has regular or painful uterine activity - she will be advised to attend for assessment and management plan.
  • Review at 41 weeks: Offer cervical assessment and discuss risks of IOL in VBAC cases, dependent on method used. Make plan for either IOL or Elective Repeat Caesarean Section. If the choice for an elective repeat Caesarean section has been made by the patient, a plan including the section date should be documented in the notes together with a plan should she labour prior to her Caesarean section date.
  • If a woman wishing VBAC presents with prelabour rupture of membranes she should be reviewed/discussed with the on call consultant and an individual plan made.
  • All women wishing VBAC should be reviewed by medical staff when attending MAU in labour or with SROM.


  1. Medical review of woman and case notes/ Badgernet. Determine that there are no new contra-indications to VBAC. 
  2. Confirm VBAC request remains appropriate and that woman wishes this.
  3. There should be rigorous adherence to routine maternal observations.
  4. Continuous fetal heart rate monitoring is advised, commencing at the onset of regular uterine activity. (If the woman declines this, inform the on call Consultant and carefully document the details of the discussion between all parties).
  5. Obtain IV access.
  6. FBC, Group and Save (only cross match if specific indication – See Blood Ordering Schedule (Obstetrics)).
  7. Alert Anaesthetic registrar to VBAC. Epidural anaesthesia is not contraindicated in a VBAC labour, although the sudden requirement for increase in analgesic need may herald uterine rupture and usually needs a senior review.
  8. FIRST STAGE: Labour should be progressive on the basis of vaginal examination at least every 4 hours.
    • “Uterine inefficiency / incoordinate activity / abnormal contraction pattern” should all prompt careful consideration of entire case and whether VBAC attempt should be continued.
    • The use of augmentation by ARM and / or syntocinon must only be considered after a critical review of case and after discussion with Consultant Obstetrician (or equivalent). Women should be informed of the 2-3 fold risk of uterine rupture (although still very rare) and 1.5 fold increased risk of caesarean section when involving induction or augmentation of labour.
    • Syntocinon dose and rate increases are specified in relevant guideline and are lower than those used in primagravida’s (see Syntocinon guideline).

    • Slow progress: first or second stage.
    • Atypical severe pain, especially if persisting between contractions: rupture can be preceded by all degrees and patterns of pain,.
    • Unexplained Maternal Tachycardia, hypotension, fainting.
    • Vaginal Bleeding.
    • Abnormal CTG.
    • Cessation of previously efficient uterine activity.
    • Loss of station of presenting part / change in abdominal contour.
  1. SECOND STAGE: This should be progressive and critical evaluation made after one hour.

Appendix 1 - Birth after Caesarean (VBAC vs ERCS) form



https://www.rcog.org.uk/globalassets/documents/guidelines/gtg_45.pdf RCOG Green top guideline No. 45 Birth after Previous Caesarean Birth October 2015

Last reviewed: 08 November 2018

Next review: 30 November 2023

Author(s): Dr James Nash; Dr Fiona Mackenzie; Dr Marcus McMillan PRM

Approved By: Clinical Director; Clinical Governance Group