Guidelines for Vaginal Birth After Previous Caesarean Birth (Replaces #147 (July 2004))
155 - Published February 2005
Objective: To provide evidence-based guidelines for the provision of
a trial of labour (TOL) after Caesarean section.
Outcome: Fetal and maternal morbidity and mortality associated with
vaginal birth after Caesarean (VBAC) and repeat Caesarean
Evidence: MEDLINE database was searched for articles published
from January 1, 1995, to February 28, 2004, using the key words
“vaginal birth after Caesarean (Cesarean) section.” The quality of
evidence is described using the Evaluation of Evidence criteria
outlined in the Report of the Canadian Task Force on the Periodic
1. Provided there are no contraindications, a woman with 1 previous
transverse low-segment Caesarean section should be offered a
trial of labour (TOL) with appropriate discussion of maternal and
perinatal risks and benefits. The process of informed consent with
appropriate documentation should be an important part of the birth
plan in a woman with a previous Caesarean section (II-2B).
2. The intention of a woman undergoing a TOL after Caesarean
section should be clearly stated, and documentation of the
previous uterine scar should be clearly marked on the prenatal
3. For a safe labour after Caesarean section, a woman should deliver
in a hospital where a timely Caesarean section is available. The
woman and her health care provider must be aware of the hospital
resources and the availability of obstetric, anesthetic, pediatric,
and operating-room staff (II-2A).
4. Each hospital should have a written policy in place regarding the
notification and (or) consultation for the physicians responsible for
a possible timely Caesarean section (III-B).
5. In the case of a TOL after Caesarean, an approximate time frame
of 30 minutes should be considered adequate in the set-up of an
urgent laparotomy (III-C).
6. Continuous electronic fetal monitoring of women attempting a TOL
after Caesarean section is recommended (II-2A).
7. Suspected uterine rupture requires urgent attention and expedited
laparotomy to attempt to decrease maternal and perinatal morbidity
and mortality (II-2A).
8. Oxytocin augmentation is not contraindicated in women undergoing
a TOL after Caesarean section (II-2A).
9. Medical induction of labour with oxytocin may be associated with an
increased risk of uterine rupture and should be used carefully after
appropriate counselling (II-2B).
10. Medical induction of labour with prostaglandin E2 (dinoprostone)
is associated with an increased risk of uterine rupture and should
not be used except in rare circumstances and after appropriate
11. Prostaglandin E1 (misoprostol) is associated with a high risk of
uterine rupture and should not be used as part of a TOL after
Caesarean section (II-2A).
12. A foley catheter may be safely used to ripen the cervix in a woman
planning a TOL after Caesarean section (II-2A).
13. The available data suggest that a trial of labour in women with
more than 1 previous Caesarean section is likely to be successful
but is associated with a higher risk of uterine rupture (II-2B).
14. Multiple gestation is not a contraindication to TOL after Caesarean
15. Diabetes mellitus is not a contraindication to TOL after Caesarean
16. Suspected fetal macrosomia is not a contraindication to TOL after
Caesarean section (II-2B).
17. Women delivering within 18 to 24 months of a Caesarean section
should be counselled about an increased risk of uterine rupture in
18. Postdatism is not a contraindication to a TOL after Caesarean
19. Every effort should be made to obtain the previous Caesarean
section operative report to determine the type of uterine incision
used. In situations where the scar is unknown, information
concerning the circumstances of the previous delivery is helpful in
determining the likelihood of a low transverse incision. If the
likelihood of a lower transverse incision is high, a TOL after
Caesarean section can be offered (II-2B).
Validation: These guidelines were approved by the Clinical Practice
Obstetrics and Executive Committees of the Society of
Obstetricians and Gynaecologists of Canada.
J Obstet Gynaecol Can 2005;27(2):164–174