Guidelines for vaginal birth after previous Caesarean birth.

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 section.

EVIDENCE

MEDLINE database was searched for articles published from January 1995 to February 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 Health Exam.

RECOMMENDATIONS

1. Provided there are no contraindications, a woman with 1 previous transverse low-segment Caesarean section should be offered a trial of labour after Caesarean 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 should be clearly stated and documentation of the previous uterine scar should be clearly marked on the prenatal record. (II-2B) 3. For a safe labour after Caesarean section, the woman should deliver in a hospital where an immediate Caesarean section is available. The woman and her health-care provider must be aware of the hospital resources and the availability of obstetric, anaesthesia, 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 immediate Caesarean. (III B) 5. Continuous electronic fetal monitoring of women attempting a TOL after Caesarean is recommended. (II-2A) 6. Suspected uterine rupture requires urgent attention and expedited laparotomy in order to attempt to decrease maternal and perinatal morbidity and mortality. (II-2A) 7. Oxytocin augmentation is not contraindicated in women undergoing a TOL after Caesarean. (II-2A) 8. 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)9. 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 after appropriate counselling. (II-2B) 10. Prostaglandin E1 (misoprostol) is associated with a high risk of uterine rupture and should not be used as part of a TOL after Caesarean. (II-2A) 11. A foley catheter may be used safely to ripen the cervix in a woman planning a TOL after Caesarean. (II-2A) 12. The available data suggest that a trial of labour in women with more than one previous Caesarean section is likely to be successful but is associated with a higher risk of uterine rupture. (II-2B) 13. Multiple gestation is not a contraindication to a TOL after Caesarean. (II-2B) 14. Diabetes mellitus is not a contraindication to TOL after Caesarean. (II-2B) 15. Suspected fetal macrosomia is not a contraindication to a TOL after Caesarean. (II-2B) 16. Women delivering within 18 to 24 months of a Caesarean section should be counselled about an increased risk of uterine rupture in labour. (II-2B) 17. Postdatism is not a contraindication to a TOL after Caesarean. (II-2B) 18. 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, TOL after Caesarean 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.