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Key messages

  • The success rate of planned vaginal birth after caesarean (VBAC) varies widely, ranging from 29 to 82 per cent.
  • Successful trial of labour after caesarean (TOLAC) leading to vaginal birth after caesarean is associated with a lower risk of complications than elective repeat caesarean (ERC).
  • Unsuccessful TOLAC leading to emergency caesarean section (EMCS) is associated with the highest risk of complications.
  • The incidence of uterine rupture during TOLAC is 0.5-3.9 per cent.
  • Continuous intrapartum fetal monitoring is essential, as the most reliable sign of uterine rupture is persistent fetal bradycardia.
  • Elective repeat caesarean should be planned for ≥39 weeks.

Birth after caesarean section

  • Elective repeat caesarean (ERC) and trial of labour after caesarean (TOLAC) have risks and benefits.
  • Up to 58 per cent of women with a previous caesarean section plan for a TOLAC.
  • When women undertake a TOLAC, 29.2-81.8 per cent have a successful vaginal birth after caesarean (VBAC).
  • Planning for birth after caesarean section will be affected by:
    • the woman's obstetric, medical and surgical history
    • the woman's preferences
    • the health service's capability and resources
    • the clinicians' training, skills and experience.

Trial of labour

Table 1. TOLAC - contraindications and precautions

Contraindications Precautions
Three or more previous caesarean sections Less than 18 months between caesarean and planned VBAC (higher risk of uterine rupture)

Previous:

  • unknown incision scar
  • classical or inverted T incision
  • hysterotomy
  • uterine rupture
  • myomectomy involving uterine cavity or extensive myometrial dissection
Single layer closure at previous caesarean section (higher risk of uterine rupture)
Placenta previa, accreta, increta, percreta Two previous lower uterine caesarean sections - refer to consultant obstetrician
Transverse lie Multiple pregnancy
Woman requesting ERC Suspected fetal macrosomia


Table 2. TOLAC and complicated pregnancies

Clinical scenario Practice points
Gestation <37+0 weeks Similar success rates to TOLAC at term
Lower risk of uterine rupture

Gestation >41+0 weeks

Previous CS = increased risk of stillbirth at >39+0 weeks
Induction of labour (IOL) is associated with increased risk of emergency caesarean section (EMCS)
IOL is associated with increased risk of uterine rupture
Escalate care to a senior obstetric clinician
Twin pregnancy Several small studies (Level 3 evidence) demonstrate a similar VBAC success rate to singleton pregnancies
Antepartum stillbirth Increased VBAC success rate
IOL is associated with increased risk of uterine rupture
Fetal macrosomia 
(EFW >4000g)
Increased risk of uterine rupture
Decreased VBAC success rate
3rd trimester US is a poor predictor of macrosomia
Maternal age >40 years Increased risk of stillbirth
Decreased VBAC success rate


Table 3. Factors increasing the likelihood of successful TOLAC

Reduction in BMI between caesarean and attempting VBAC
Maternal age <30 years
Maternal BMI <30
Prior caesarean not related to arrest of labour
Spontaneous onset of labour <41 weeks
Cervical dilatation greater than 4cm on admission

Modes of birth - benefits

Table 4. Benefits associated with modes of birth

Mode of birth Benefits
Vaginal birth after caesarean Woman's satisfaction in achieving a vaginal birth, if this is desired
Earlier mobilisation and discharge from hospital
Reduced risk of maternal morbidity in current and future pregnancies
Increased rates of successful breastfeeding initiation
Elective repeat caesarean Reduced risk of uterine rupture
Reduced risk of stillbirth >39+0 weeks
Avoidance of increased risks associated with emergency caesarean
Avoidance of pelvic floor trauma
Reduced risk of newborn hypoxic ischaemic encephalopathy (HIE)

 

Modes of birth - risk of uterine rupture

Uterine rupture is the complete disruption of all uterine layers, leading to changes in maternal or fetal status.

Practice points

  • The risk of uterine rupture is lowest with ERC
  • The risk of uterine rupture is highest when a TOLAC leads to an EMCS
  • When women labour, the risk of uterine rupture is lowest when spontaneous labour leads to a VBAC
  • IOL increases the risk of uterine rupture
  • Types and frequencies of major maternal and neonatal outcomes of uterine rupture include:
    • Hysterectomy: 14 to 33 per cent
    • Maternal death: 0.21 per cent
    • Neonatal death: 5 per cent
    • Severe neonatal neurologic morbidity: 6 to 8 per cent.

Table 5. Risk of uterine rupture by mode of birth

Mode of birth Risk of uterine rupture
Vaginal birth after caesarean (VBAC) 0.1-1.9% 
Elective repeat caesarean (ERC) <0.02% 
Emergency caesarean section (EMCS) 0.7-3.9%

 

Modes of birth - other complications

Table 6. Complications by intended mode of birth

  Vaginal birth after caesarean Elective repeat caesarean section
Maternal complications
Blood transfusion 2 per 100 / 2.0% 1 per 100 / 1.0%
Maternal mortality 4 per 100,000 / 0.004% 13 per 100,000 / 0.013%
Serious complications in future pregnancies N/A Increased likelihood of placenta praevia and morbidly adherent placenta
Endometritis No significant difference in risk

Fetal and newborn complications

Antepartum stillbirth whilst awaiting spontaneous labour beyond 39+0 weeks

10 per 10,000 / 0.1%

N/A

Delivery-related perinatal mortality

0.04%

0.01%

Transient respiratory morbidity

2-3 per 100 / 2.0-3.0%

4-6 per 100 / 4.0-6.0%

Hypoxic ischaemic encephalopathy (HIE)

8 per 10,000 / 0.08%

<1 per 10,000 / <0.01%

Antenatal care

Practice points

  • Review details of the previous caesarean
  • Discuss intentions for future pregnancies
  • Provide women with information and advice on:
    • contraindications to and precautions for TOLAC (Table 1)
    • TOLAC and complicated pregnancies, if applicable (Table 2)
    • factors that increase the likelihood of successful TOLAC (Table 3)
    • benefits associated with modes of birth (Table 4)
    • risks of uterine rupture (Table 5)
    • other maternal, fetal and newborn complications (Table 6)
  • Provide information early in pregnancy to facilitate informed decision making
  • Document a management plan for intrapartum care
  • Agree on a management plan for spontaneous labour, planned caesarean and EMCS
  • Discuss a management plan if spontaneous labour does not occur by 40 weeks and provide information about the increased risk of uterine rupture associated with IOL
    (see: Induction of labour)
  • Set date for caesarean and consent
  • Routine antenatal care.

If planning for VBAC, ensure the hospital has the capacity to perform an emergency caesarean section and manage a uterine rupture.

Intrapartum care

  • Review plan with the woman and revise as indicated
  • Ensure:
    • IV access with a 16g cannula
    • blood sent for Group and Hold
    • record of progress on a partogram
    • continuous electronic fetal monitoring (CEFM)
  • Inform anaesthetics, theatre, paediatric and nursery services of the woman's admission for TOLAC
  • Provide continuous midwifery support with 1:1 care during established labour
  • Oral intake as per normal intrapartum care
  • Epidural analgesia is not contraindicated
  • Escalate to senior obstetric clinician if there is a lack of progress in first or second stages
    • Refer to local intrapartum care guidelines for expected progress
  • Active management of 3rd stage is recommended
  • Routine exploration of the uterus to detect a dehisced scar after a vaginal birth is not recommended.

Remain alert for signs of uterine rupture:

  • Prolonged, persistent, profound fetal bradycardia
  • Abnormal FHR pattern suggesting fetal compromise
  • Abdominal pain: acute onset of scar tenderness
  • Any atypical pain:
    • chest pain
    • shoulder tip pain
    • pain previously controlled by analgesia
    • pain between contractions
  • Cessation of previously efficient uterine activity
  • Loss of station of presenting part
  • Abnormal labour progress
  • Vaginal bleeding
  • Maternal tachycardia, hypotension or shock.

If there is any sign of uterine rupture, initiate emergency response as per local guidelines.

Postpartum care

Practice points

  • Offer the woman the opportunity to debrief with clinicians involved in her intrapartum care
  • Offer referral to social work, pastoral or spiritual care as indicated
  • Provide information about planning for the next birth
  • Ensure that the woman's Maternal and Child Health Nurse and GP receive a complete discharge summary.

Information and decision making

Women who have had a previous caesarean section should have the opportunity to make informed decisions about their care and treatment, in partnership with the clinicians providing their care.

Good communication between clinicians and women is essential. Treatment, care and information provided should:

  • take into account women's individual needs and preferences
  • be supported by evidence-based, written information tailored to the needs of the individual woman
  • be culturally appropriate
  • be accessible to women, their partners, support people and families and take into account any specific needs such as physical or cognitive disabilities or limitations to their ability to understand spoken or written English.

Patient information options:

Documentation

The following should be documented in the woman's hospital medical record and (where applicable) her hand-held medical record:

  • details of the woman's previous caesarean - labour (if applicable), indication, type of incision
  • management plan
  • discussion of the risks and benefits of recommended management
  • discussion of the woman's questions
  • consultation, referral and escalation.

More information

Audit and performance improvement

All maternity services should have processes in place for:

  • auditing clinical practice and outcomes
  • providing feedback to clinicians on audit results
  • addressing risks, if identified
  • implementing change, if indicated.

For further information, or assistance with auditing, please contact the Maternity and Newborn Clinical Network: maternityehandbook@safercare.vic.gov.au

Auditable standards for Birth After Caesarean:

  • number of women eligible to attempt TOLAC
  • adherence to standards of care
  • Perinatal Services Performance Indicator (PSPI) 4a - Rate of women who planned for vaginal birth following a primary caesarean section (Victorian maternity services)
  • PSPI 4b - Rate of women attempting a VBAC who had a planned vaginal birth following a primary caesarean section (Victorian maternity services).

References

Abbreviations

CEFM Continuous electronic fetal monitoring
CTG Cardiotocograph
ELCS Elective caesarean section
EMCS Emergency caesarean section
ERC Elective repeat caesarean
IOL Induction of labour
LUSCS Lower uterine segment caesarean section
NBAC Next birth after caesarean
PSPI Perinatal Services Performance Indicators
TOLAC Trial of labour after caesarean
VBAC Vaginal birth after caesarean

Get in touch

Maternity and Newborn Clinical Network
Safer Care Victoria

Version history

First published: May 2018

Last web update: May 2018

Review by: May 2020

Uncontrolled when downloaded

Page last updated: 18 Dec 2018