Induction of Labour

Objective: To review the most current literature in order to provide evidence-based recommendations to obstetrical care providers on induction of labour. Options: Intervention in a pregnancy with induction of labour. Outcomes: Appropriate timing and method of induction, appropriate mode of delivery, and optimal maternal and perinatal outcomes. Evidence: Published literature was retrieved through searches of PubMed, CINAHL, and The Cochrane Library in 2010 using appropriate controlled vocabulary (e. g., labour, induced, labour induction, cervical ripening) and key words (e. g., induce, induction, augmentation). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date or language restrictions. Searches were updated on a regular basis and incorporated in the guideline to the end of 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Values: The evidence in this document was rated using criteria described in the Report of the Canadian Task Force on Preventative Health Care (Table 1). Summary Statements 1. Prostaglandins E-2 (cervical and vaginal) are effective agents of cervical ripening and induction of labour for an unfavourable cervix. (I) 2. Intravaginal prostaglandins E-2 are preferred to intracervical prostaglandins E-2 because they results in more timely vaginal deliveries. (I) Recommendations 1. The indication for induction must be documented, and discussion should include reason for induction, method of induction, and risks, including failure to achieve labour and possible increased risk of Caesarean section. (III-B) 2. If induction of labour is unsuccessful, the indication and method of induction should be re-evaluated. (III-B) 3. Inductions should not be performed solely for suspected fetal macrosomia. (III-D) 4. Inductions should not be performed solely because of patient or care provider preference. (III-D) 5. Health care providers should assess the cervix (using the Bishop score) to determine the likelihood of success and to select the appropriate method of induction. (II-2A) 6. The Bishop score should be documented. (III-B) 7. Care providers need to consider that induction of women with an unfavourable cervix is associated with a higher failure rate in nulliparous patients and a higher Caesarean section rate in nulliparous and parous patients. (II-2A) 8. Every woman should ideally have an ultrasound, preferably in the first trimester, to confirm gestational age. (I-A) 9. Institutions should have quality assurance programs and induction policies, including safety tools such as checklists, to ensure that inductions are performed only for acceptable indications. (II-2B) 10. Women should be offered induction of labour between 41+0 and 42+0 weeks as this intervention may reduce perinatal mortality and meconium aspiration syndrome without increasing the Caesarean section rate. (I-A) 11. Women who chose to delay induction >41+0 weeks should undergo twice-weekly assessment for fetal well-being. (I-A) 12. Intracervical Foley catheters are acceptable agents (II-2B) that are safe both in the setting of a vaginal birth after Caesarean section (I-B) and in the outpatient setting. (II-2B) 13. Double lumen catheters may be considered a second-line alternative. (II-2B) 14. Prostaglandins E-2 (cervical and vaginal) should not be used in the setting of vaginal birth after Caesarean section due to the increased risk of uterine rupture. (II-2D) 15. Vaginal prostaglandins E-2 may be considered with ruptured membranes at term and can be used in this setting. (I-A) 16. Misoprostol can be considered a safe and effective agent for labour induction with intact membranes and on an inpatient basis. (I-A) 17. Misoprostol should not be used in the setting of vaginal birth after Caesarean section due to the increased risk of uterine rupture. (II-3D) 18. Oxytocin should be started no earlier than 4 hours after the last dose of misoprostol. (III-B) 19. Amniotomy should be reserved for women with a favourable cervix. Particular care should be given in the case of unengaged presentation because there is a risk of cord prolapse. (III-B) 20. After amniotomy, oxytocin should be commenced early in order to establish labour. (III-B) 21. In the setting of ruptured membranes at term, oxytocin should be considered before expectant management. (I-A) 22. Women positive for group B streptococcus should be started on oxytocin as early as possible after ruptured membranes in order to establish labour within 24 hours. (III-B) 23. Both high-and low-dose oxytocin may be considered within a hospital protocol. (III-B) 24. Because of the various concentrations, oxytocin infusion rates should always be recorded in mU/min rather than mL/hr. (III-L) 25. Oxytocin induction maybe considered in the hospital setting of vaginal birth after Caesarean section. (II-3B)