Vaginal Birth after Caesarean Section (VBAC)

Overview:An attempted vaginal birth for women with a single previous low transverse Caesarean section is associated with a lower risk of complications for mothers than routine repeat caesarean it’s a safe option for the majority of women.

Aim

To present the best available evidence to facilitate antenatal counselling in women with prior CS birth and to formulate intrapartum management

Introduction:

Increasing rates of primary caesarean section have increased the population with a history of prior caesarean delivery. Women with previous CS may be offered either planned Vaginal Birth after Caesarean Section (VBAC) or elective repeat caesarean section (ELCS)

Although there are no randomized controlled trials comparing planned VBAC with planned ELCS, VBAC remains a safe option and should be recommended to women with a prior history of one uncomplicated lower segment transverse caesarean section in an otherwise uncomplicated pregnancy at term¹

Babies born by ELCS are at increased risk of breathing difficulties (stratified by gestation, the risk is double that of a neonate delivered vaginally)2

Women who have achieved a vaginal birth after LSCS have an enhanced likelihood of success again ( 87-90%) but continue to have the small increased risk of scar rupture associated with any VBAC.

Factors associated with a low success rate for VBAC: Induced labour, no previous vaginal birth. BMI>30, previous CS for labour dystocia, birth weight >4 kg, previous preterm CS birth, less than 2 years from previous CS birth, advanced maternal age, short stature (success rate only 40%).

Absolute Contraindication to VBAC

  • Previous uterine rupture (risk of recurrence unknown)
  • Previous high vertical classical CS (risk of uterine rupture 2-9%)
  • Three or more previous CS deliveries (risk of rupture unknown)
  • There is insufficient, and conflicting, evidence on whether the risk of uterine rupture is increased in women with previous myomectomy or prior complex uterine surgery, as this depends on where the uterine cavity was opened, and how thin the resulting myometrium is post operatively.

Relative contraindications where VBAC may be considered

  • Women with a prior history of two uncomplicated low transverse CS in an otherwise uncomplicated pregnancy at term, with no contraindication for vaginal birth, who have been fully informed by a consultant may be considered suitable for planned VBAC
  • Women with previous uterine incision other than uncomplicated low transverse CS incision, who wish to consider VBAC, should be assessed by a consultant with full access to the details of the previous surgery. Provided the woman has been fully informed by a consultant of these increased risks and a comprehensive individualised risk analysis has been undertaken of the indication for and the nature of previous CS then planned VBAC maybe supported

Planned VBAC in special circumstances

  • Pre-term birth: women who are preterm and considering VBAC, should be informed that planned preterm VBAC has similar success rates to planned VBAC at term, but with a lower risk of uterine rupture
  • Twins/fetal macrosomia/short inter-delivery interval: a cautious approach is advised when considering planned VBAC in these women as there’s uncertainty in the safety and efficacy of planned VBAC

Antenatal counselling

Women should be counselled

  • about the maternal and perinatal risks and benefits of planned VBAC and ELCS when deciding the mode of delivery,
  • there should be a review of the operative notes of the previous CS to identify the indication, type of uterine incision, operative findings including any evidence of cephalo-pelvic disproportion (CPD)and
  • any peri-operative complications that may require an elective caesarean section.
  • Planned VBAC carries a risk of uterine scar rupture 0.2-0.7% (22-74/10000), although a rare complication, it is associated with significant maternal and perinatal morbidity. There is virtually no risk of scar rupture with ELCS
  • Planned VBAC carries a 1% additional risk of blood transfusion
  • Planned ELCS increases the risk of serious complications in future pregnancies [injury to bladder, bowel or ureter, haemorrhage needing blood transfusion, infection, thromboembolism, placenta problems (praevia/accrete/percreta), hysterectomy and ITU admission]
  • VBAC carries a risk of 2-3/10000 of perinatal death when compared to ELCS; it is comparable to the risk of women having their first birth
  • VBAC reduces the risk of respiratory problems in the newborn (TTN, RDS)
  • The woman’s intended number of future pregnancies is an important factor to consider during the decision-making process for either planned VBAC or ELCS
  • Women considering VBAC should be informed that the overall the chances of a successful planned VBAC in the best series is up to 70-75%

The antenatal counselling should be documented in the woman’s hospital healthcare record. See appendix 1 for checklist used. This can also be printed from the stationery section of the guidelines website.Suitability for VBAC should be clearly documented together with any particular instructions for intrapartum care. Women should be provided with patient information leaflet on VBAC at the time ofthe consultation

Women should be advised that the majority of women who present in spontaneous labour will reach full dilatation within 10-12 hours from theonset of regular uterine contractions lasting 45-60 seconds. As all mothers with a previous LSCS are under consultant care, the rate of progress considered normal is 1cm per hour do we need this last sentence? Can’t we leave it out?

For women having a scheduled (elective) repeat LSCS there ahould be a plan for the event of labour starting prior to thisdateof a planned elective caesarean section, should be documented (10% of women scheduled for ELCS go in to labour before the 39th week)

A final decision for mode of delivery should be agreed on by 40weeks of gestation for those women still pregnant.

Intrapartum support and intervention during planned VBAC

Place of Labour:

Women should be advised that a plannedVBAC

  • should be conducted on the main delivery suite,
  • with continuous intrapartum care /monitoring and available resources for immediate CS, advanced neonatal resuscitation and on site blood transfusion (1, 2)
  • Continuous intrapartum maternal and fetal monitoring is necessary to enable prompt identification and management of uterine scar rupture
  • Early diagnosis of uterine scar rupture followed by expeditious laparotomy and resuscitation is essential to reduce the associated morbidity and mortality in mother and infant.

Maternal monitoring in labour:

  • Secure intravenous access on admission for delivery and send blood for FBC and G&S
  • Give Ranitidine 150mg orally every 6-8 hours
  • Critical review of progress of labour, the midwife should closely review the progress of labour with abdominal palpation and vaginal examination every 4 hours using a partogram with action lines drawn on it.
  • Lack of progress should be discussed with the Registrar and the Consultant on call

Signs and symptoms of scar rupture (one or more may be present):

  • Abnormal CTG (change of baseline rate either increase or decrease, prolonged bradycardia)
  • Severe abdominal pain persisting between contractions, with or without an epidural un situ1,3
  • Chest pain or shoulder tip pain or sudden onset shortness of breath (referred diaphragmatic pain)
  • Acute onset scar tenderness
  • Abnormal vaginal bleeding or haematuria
  • Cessation of previously efficient uterine activity
  • Maternal tachycardia, hypotension or shock
  • Loss of station of the presenting part

Fetal monitoring in labour:

  • Women should be advised to have Continuous Electronic Fetal Monitoring (CEFM) following the onset of uterine contractions for the duration of planned VBAC 2,3,,4
  • If it is discussed antenatally that the mother wishes to have intermittent fetal heart auscultation, this should be clearly documented in the woman’s hospital healthcare record.

Request to birth at home/birth centre or in water:

Some women will make a choice to have their baby at birth centre, home or in water.

Ideally, this request will have been explored in detail by the community midwife, with input from her Supervisor of Midwives in the case of home birth requests, or the consultant midwife.. A clear care plan for labour must be documented in the records

Induction and Augmentation

Women should be informed of the 2-3 fold increased risk of uterine rupture and around 1.5 fold increased risk of CS in induced and or augmented labour compared with spontaneous onset of labour1, 3

Induction with prostaglandins

Cervical ripening with prostaglandins is probably safe in selected cases but numbers studied are small, 6, 7,8, 9

The process should be discussed with the woman and then approved by a consultant2 at 40_41 weeks

Augmentation

Although augmentation is not contraindicated, it should only be preceded by careful obstetric assessment, maternal counselling and by a consultant led decision 1

The guideline on the use of syntocinon should be followed

Procedure / All Consultants
IOL PG / Consultant authorisation required
IOL ARM + Syntocinon / Consultant authorisation required
Augment dysfunctional labour / Authorisation required from delivery suite Consultant
Augment 2⁰arrest / No
CEFHRM / Yes, unless documented in notes
Epidural / Yes
Expected rate of progress
I can’t see from reference cited that it says 1cm hour – I have cut and pasted what document says. / 1 cm hr 1There should be careful serial cervical assessments, preferably by the same person, for both augmented
and non-augmented labours, to ensure that there is adequate cervicometric progress, thereby allowing
the planned VBAC to continue.

Postnatal Care

  • Post delivery, the woman should have the usual monitoring of maternal observations, including vaginal loss.Digital palpation/ examination of scar is only necessary if there is persistent postpartum bleeding 9
  • Encourage early skin to skin contact and breast feeding
  • Bladder care should be as described in the Bladder Care guideline

Debriefing

  • Women who havenot achieved a vaginal birth, should be offered a discussion as to the reason for the caesarean section and the implication for future pregnancies, before they are discharged if possible The discharge papers should included the indications for emergency LSCS .

Auditable standards:

1.All women who have had one previous delivery by caesarean section will be given and will discuss the VBAC leaflet on the booking appointment. This will be documented in the maternal hand held record

2.All women who have had one previous delivery by caesarean section will be assessed for their suitability for vaginal delivery by the 20 weeks appointment (from May 2011). This will be documented in the “Check sheet for counselling women who have had one previous LSCS” and filed in the maternal health record.

3.All women whose planned mode of delivery is VBAC will have an individual management plan for labour that includes point of contact when labour starts, reminder to mention previous LSCS, plan for monitoring FHR in labour and recommendation of IV access. This will be documented in the “Check sheet for counselling women who have had one previous LSCS” and filed in the maternal health record.

4.All women whose planned mode of delivery is VBAC will have a plan made should the labour not commence as planned / post EDD by the 39-40 weeks appointment. This will be documented in the “Check sheet for counselling women who have had one previous LSCS” and filed in the maternal health record.

5.All women who have had one previous delivery by caesarean section will be given and will discuss the VBAC leaflet on the booking appointment. This will be documented in the maternal hand held record.

References:

  1. Birth after caesarean birth Green Top Guidelines No 45. RCOG 2007?
  2. Morrison JJ, Rennie JM, Milton PJ Neonatal respiratory morbidity and mode of delivery at term; influence of timing of elective caesarean section Br J Obstet Gynaecol. 1995; 02, 101
  3. Caesarean section. NICE 2004 – we should update to new guidance….
  4. The use of electronic fetal monitoring evidence based clinical guideline No 8 RCOG 2001
  5. Hadley CB et al (1986) an evaluation of the relative risks of a trial of labour versus elective repeat caesarean section. Am.J.Perinatal 3:107-114
  6. Williams MA,Luthy DA,Zingheim RW et al(1995) Production prostaglandin E2 gel prior to induction of labour in women with previous caesarean section
  7. Stone JL,Lockwood CJ,Berkowitz G et al (1984) use of cervical prostaglandin E2 in patients with previous CS.Br J Obstet Gynaecol 91: 7-10
  8. Mackenzie IZ,Bradley S,Embrey MP(1997) Vaginal prostaglandins and labour induction for patients previously delivered by caesarean section. Am J Perinatal 14: 157-160
  9. Flamm BL,Anton D,Goings JR et al. (1987) prostaglandin E2 for cervical ripening: multicenter study of patients with prior caesarean delivery.Obstet Gynecol 70: 709-712
  10. Perrotin F,Marret H, Fignon A et al. (1999) scarred uterus is routine exploration of the caesarean scar after vaginal birth always necessary? J Gynecol Obstet Biol report (Paris) 28:253-262

Authors:Dr Hirsi-Farah & Miss Pat Street

Written:June 2009

Revised:September 2011, March 2012 (J Siddall & Annette Weavers)

Appendix 1 – Checksheet for counselling women who have had 1 previous LSCS

Monitoring:

The audit team that will audit the above auditable standards will be formed by:

  • A midwife and/or a doctor and/or a maternity support worker
  • Audit and quality midwife
  • A clinical audit facilitator

The audit will compare results with previous audits, if applicable. The audit will review documentation stated in the maternal health records as evidence of compliance with standards.

The audit will be completed prospectively or retrospectively:

For first-time audits: within the first 9 months of each financial year

For repeat audits: within the timeframe stated by previous audit’s risk priority.

Plan following audit results for all standards audited, this would subject to earlier re-audit if concerns are raised from risk management about this particular area.

Results / Plan / Risk
Priority
If < 75% compliance / Implement action plan and re-audit within 3 months from completion of report / 1
If ≥ 75% compliance and results ≤ than previous audit (when applicable) / Implement action plan and re-audit within 6 months from completion of report / 2
If ≥ 75% compliance and results ≥ than previous audit (when applicable) / Implement action plan and re-audit next financial year from completion of report / 3

The results will be disseminated depending on the risk priority.

Risk
Priority / Dissemination
1 / Presented in at least one of the following meetings: Maternity Audit Forum, Maternity Clinical Governance, Morbidity & Mortality, Combined anaesthetic team, midwifery services meeting or local ward forums.
Uploaded in Datix for staff and patients access
RBHFT Maternity Newsletter
Special measures identified in action plan
2 / Presented in one of the above meetings
Uploaded in Datix for staff and patients access
RBHFT Maternity Newsletter
3 / Uploaded in Datix for staff and patients access
RBHFT Maternity Newsletter

The dissemination on results and implementation of action plans and timely re-audit will be coordinated by the Audit and Quality Midwife and reported to the Maternity Clinical Audit Committee on a monthly basis. This committee reports to Maternity Clinical Governance monthly

Author: / Jane Siddall, Annette Weavers (orig. Pat Street & Saud Hirsi-Farah) / Date: / March 2012
Job Title: / Consultant Obstetrician, Consultant Midwive (Consultant Obstetrician & Specialist Registrar) / Review Date: / March 2015
Policy Lead: / Clinical Director Maternity & Children’s Services / Version: / 2.0 ratified May 12 CG mtg
Location: / Intranet, maternity dept, guidelines policies & protocols, obst & midw, Intrapartum

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