Guideline No. 432a: Cervical Ripening and Induction of Labour – General Information

Abstract

ObjectiveThis 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 PopulationAll pregnant patients. Benefits, Harms, and CostsConsistent 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. EvidenceLiterature 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 Grey (unpublished) literature was identified by searching the websites of health technology assessment and health technology related agencies, clinical practice guideline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 MethodsThe 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 AudienceAll providers of obstetrical care. RECOMMENDATIONS1.Induction of labour should be a shared decision between the pregnant individual and the care provider, with respect for an individual’s choice. The consent discussion should be documented and include the benefits and risks of both induction and expectant management, along with the induction process, including methods, timing, and how these may affect the patient and fetus (strong, moderate).2.All pregnant individuals should be offered a first-trimester dating ultrasound at 8–12 weeks gestation to confirm gestational age (strong, high).3.Regular sweeping of the membranes may be offered from 38 weeks gestation to reduce the incidence of late term pregnancy. Group B Streptococcus is not a contraindication to a membrane sweep (conditional, low).4.Castor oil, nipple stimulation, and breast compression can reduce the need for induction of labour and may be offered to low-risk individuals at term (conditional, low).5.Late term induction of labour should be offered at or after 41 weeks gestation (strong, high).6.Suspected macrosomia or large for gestational age alone is not an indication for induction of labour before 39 weeks (conditional, low).7.Cesarean delivery may be considered for ultrasound estimated fetal weight >4500 g in the presence of diabetes and estimated fetal weight >5000 g in the absence of diabetes (conditional, moderate).8.Routine elective induction of labour at 39 weeks gestation is not recommended. If requested, the provider should take into account patient preferences, local health care resources, and local cesarean delivery rates associated with induction (strong, moderate).9.Induction of labour may be offered at 39 weeks gestation for advanced maternal age (≥40 years) (strong, high).10.There is insufficient evidence that induction of labour is associated with maternal or fetal benefits for pregnancies conceived via assisted reproductive technologies (conditional, low).11.For patients who are positive for group B Streptococcus with a singleton pregnancy and term rupture of membranes, IOL should be offered as soon as resources allow, and antibiotic prophylaxis should be started while awaiting IOL (conditional, moderate).12.For patients who are negative for group B Streptococcus with a singleton pregnancy and term rupture of membranes, IOL may be offered as soon as resources allow. Expectant management for up to 24 hours is also acceptable. Digital pelvic exams should be avoided until active labour begins, and then done only when indicated (strong, moderate).13.Either oral misoprostol or oxytocin can be used for induction of labour in the setting of term pre-labour rupture of membranes, regardless of Bishop score (strong, high).14.The modified Bishop score should be used and documented to determine if cervical ripening is required (strong, high).15.Fetal presentation should be confirmed by abdominal exam and/or ultrasound prior to inducing labour (strong, high).16.Quality assurance audits for induction of labour practices are important within health care organizations. Important quality measures include the indication for induction, the induction approach, and outcomes (strong, high).