Guideline No. 432b: Cervical Ripening

Objective This guideline presents evidence and recommendations for cervical ripening and induction of labour. It aims to provide information to birth attendants and pregnant individuals on optimal perinatal care while avoiding unnecessary obstetrical intervention. Target Population All pregnant patients. Benefits, Harms, and Costs Consistent interprofessional use of the guideline, appropriate equipment, and trained professional staff enhance safe intrapartum care. Pregnant individuals and their support person(s) should be informed of the benefits and risks of induction of labour. Evidence Literature published to March 2022 was reviewed. PubMed, CINAHL, and the Cochrane Library were used to search for systematic reviews, randomized controlled trials, and observational studies on cervical ripening and induction of labour. Grey (unpublished) literature was identified by searching the websites of health technology assessment and health technology related agencies, clinical practice guideline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. Validation Methods The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional [weak] recommendations). Intended Audience All providers of obstetrical care. RECOMMENDATIONS 1.Cervical ripening is recommended when the modified Bishop score is less than 7 (strong, high). 2.Health care providers should not routinely offer amniotomy or oxytocin (individually or in combination) until the modified Bishop score is 7 or greater (strong, high). 3.Should cervical ripening and/or IOL be unsuccessful, health care providers should consider an alternative or combined method of cervical ripening and/or IOL before proceeding with cesarean delivery (strong, high). 4.Health care providers should consider balloon catheters first-line agents for cervical ripening whenever feasible, as they are safe and effective, including in an outpatient setting and in a trial of labour after cesarean. (strong, high). 5.Health care providers may use either prostaglandin E1 or prostaglandin E2 vaginal gel or insert to achieve safe and effective cervical ripening (strong, high). Providers should consider the degree of ripening required (based on the Bishop score) and the desire for outpatient management when choosing a prostaglandin for cervical ripening (conditional, moderate). 6.Health care providers may use prostaglandin and balloon catheters concurrently for cervical ripening (conditional, moderate). 7.Health care providers can use prostaglandin E2 for outpatient cervical ripening when there is a normal electronic fetal monitoring tracing (strong, moderate). 8.Health care providers can use prostaglandin E1 for inpatient management of cervical ripening (strong, high). If a break from cervical ripening is required, patients can be sent home from the hospital 2 hours after an oral dose and 4 hours after a vaginal dose if electronic fetal monitoring is normal (strong, moderate). 9.Health care providers should be cautious when using any prostaglandin in a potentially compromised fetus (strong, moderate). 10.Health care providers may use prostaglandin E1 in the first or second trimester, but not in the third trimester with previous cesarean delivery or significant uterine surgery (strong, moderate).