SOGC Clinical Practice Guideline| Volume 45, ISSUE 1, P35-44.e1, January 2023

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



      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.


      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 Grey (unpublished) literature was identified by searching the websites of health technology assessment and health technology related agencies, clinical practice guideline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.


      • 1.
        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).



      ART (assisted reproductive technologies), CD (cesarean delivery), GBS (group B Streptococcus), IOL (induction of labour), PROM (pre-labour rupture of membranes)
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        • D'Souza R.
        • Ashraf R.
        • Foroutan F.
        Prediction models for determining the success of labour induction: a systematic review and critical analysis.
        Best Pract Res Clin Obstet Gynaecol. 2022; 79: 42-54
        • Burnett Jr., J.E.
        Preinduction scoring: an objective approach to induction of labor.
        Obstet Gynecol. 1966; 28: 479-483
        • Butt K.
        • Lim K.I.
        Guideline no. 388-determination of gestational age by ultrasound.
        J Obstet Gynaecol Can. 2019; 41: 1497-1507
        • Finucane E.M.
        • Murphy D.J.
        • Biesty L.M.
        • et al.
        Membrane sweeping for induction of labour.
        Cochrane Database Syst Rev. 2020; : CD000451
        • Carbone L.
        • De Vivo V.
        • Saccone G.
        • et al.
        Sexual intercourse for induction of spontaneous onset of labor: a systematic review and meta-analysis of randomized controlled trials.
        J Sex Med. 2019; 16: 1787-1795
        • Okoro O.
        • Ugwu E.
        • Dim C.
        • et al.
        Effectiveness of castor oil in preventing post-term pregnancy in low resource setting: a randomized controlled trial.
        Am J Clin Med Res. 2019; 7: 37-43
        • Gilad R.
        • Hochner H.
        • Savitsky B.
        • et al.
        Castor oil for induction of labor in post-date pregnancies: a randomized controlled trial.
        Women Birth. 2018; 31: e26-e31
        • Kavanagh J.
        • Kelly A.J.
        • Thomas J.
        Breast stimulation for cervical ripening and induction of labour.
        Cochrane Database Syst Rev. 2005; 3: CD003392
        • Parikh L.
        • Singh J.
        • Timofeev J.
        • et al.
        Timing and consequences of early term and late term deliveries.
        J Matern Fetal Neonatal Med. 2014; 27: 1158-1162
        • Helle E.
        • Andersson S.
        • Häkkinen U.
        • et al.
        Morbidity and health care costs after early term birth.
        Paediatr Perinat Epidemiol. 2016; 30: 533-540
        • March of Dimes
        Healthy babies are worth the wait. White Plains (NY).
        (Available at:) (Accessed on August 26, 2022)
      1. ACOG committee opinion no 579: definition of term pregnancy.
        Obstet Gynecol. 2013; 122: 1139-1140
        • Buckles K.
        • Guldi M.
        Worth the wait? The effect of early term birth on maternal and infant health.
        J Policy Anal Manage. 2017; 36: 748-772
        • Seikku L.
        • Gissler M.
        • Andersson S.
        • et al.
        Asphyxia, neurologic morbidity, and perinatal mortality in early-term and postterm birth.
        Pediatrics. 2016; 137e20153334
        • Middleton P.
        • Shepherd E.
        • Crowther C.A.
        Induction of labour for improving birth outcomes for women at or beyond term.
        Cochrane Database Syst Rev. 2018; 5: CD004945
        • Delaney M.
        • Roggensack A.
        Guidelines for the management of pregnancy at 41+0 to 42+0 weeks.
        J Obstet Gynaecol Can. 2008; 30: 800-810
        • Mandruzzato G.
        • Alfirevic Z.
        • Chervenak F.
        • et al.
        Guidelines for the management of postterm pregnancy.
        J Perinat Med. 2010; 38: 111-119
        • Macrosomia
        ACOG practice bulletin, number 216.
        Obstet Gynecol. 2020; 135: e18-e35
        • Royal College of Obstetricians and Gynaecologists
        Shoulder dystocia (green-top guideline no. 42).
        2nd edition. 2012 (Available at:) (Accessed on August 26, 2022)
        • Magro-Malosso E.R.
        • Saccone G.
        • Chen M.
        • et al.
        Induction of labour for suspected macrosomia at term in non-diabetic women: a systematic review and meta-analysis of randomized controlled trials.
        BJOG. 2017; 124: 414-421
        • Malin G.L.
        • Bugg G.J.
        • Takwoingi Y.
        • et al.
        Antenatal magnetic resonance imaging versus ultrasound for predicting neonatal macrosomia: a systematic review and meta-analysis.
        BJOG. 2016; 123: 77-88
        • Cheng E.R.
        • Declercq E.R.
        • Belanoff C.
        • et al.
        Labor and delivery experiences of mothers with suspected large babies.
        Matern Child Health J. 2015; 19: 2578-2586
        • Boulvain M.
        • Senat M.-V.
        • Perrotin F.
        • et al.
        Induction of labour versus expectant management for large-for-date fetuses: a randomised controlled trial.
        Lancet. 2015; 385: 2600-2605
        • Vercellini P.
        • Fumagalli M.
        • Consonni D.
        • et al.
        Historic cohort study on mode of delivery of a macrosomic baby: the women's point of view.
        Acta Obstet Gynecol Scand. 2015; 94: 1235-1244
        • Ellis J.A.
        • Brown C.M.
        • Barger B.
        • et al.
        Influence of maternal obesity on labor induction: a systematic review and meta-analysis.
        J Midwifery Womens Health. 2019; 64: 55-67
        • Paidas Teefey C.
        • Reforma L.
        • Koelper N.C.
        • et al.
        Risk factors associated with cesarean delivery after induction of labor in women with class iii obesity.
        Obstet Gynecol. 2020; 135: 542-549
        • Cedergren M.I.
        Maternal morbid obesity and the risk of adverse pregnancy outcome.
        Obstet Gynecol. 2004; 103: 219-224
        • Palatnik A.
        • Kominiarek M.A.
        Outcomes of elective induction of labor versus expectant management among obese women at ≥39 weeks.
        Am J Perinatol. 2020; 37: 695-707
        • Maxwell C.
        • Gaudet L.
        • Cassir G.
        • et al.
        Guideline no. 391-pregnancy and maternal obesity part 1: pre-conception and prenatal care.
        J Obstet Gynaecol Can. 2019; 41: 1623-1640
        • Grobman W.A.
        • Rice M.M.
        • Reddy U.M.
        • et al.
        Labor induction versus expectant management in low-risk nulliparous women.
        N Engl J Med. 2018; 379: 513-523
        • Grobman W.A.
        • Caughey A.B.
        Elective induction of labor at 39 weeks compared with expectant management: a meta-analysis of cohort studies.
        Am J Obstet Gynecol. 2019; 221: 304-310
        • Souter V.
        • Nethery E.
        • Levy B.
        • et al.
        Elective induction of labor in nulliparas: has the ARRIVE trial changed obstetric practices and outcomes?.
        Am J Obstet Gynecol. 2022; 226: S83-S84
        • Dong S.
        • Bapoo S.
        • Shukla M.
        • et al.
        Induction of labour in low-risk pregnancies before 40 weeks of gestation: a systematic review and meta-analysis of randomized trials.
        Best Pract Res Clin Obstet Gynaecol. 2022; 79: 107-125
        • Lean S.C.
        • Derricott H.
        • Jones R.L.
        • et al.
        Advanced maternal age and adverse pregnancy outcomes: a systematic review and meta-analysis.
        PLoS One. 2017; 12e0186287
        • Rydahl E.
        • Declercq E.
        • Juhl M.
        • et al.
        Cesarean section on a rise-does advanced maternal age explain the increase? A population register-based study.
        PLoS One. 2019; 14e0210655
        • Allen V.M.
        • Wilson R.D.
        • Cheung A.
        Pregnancy outcomes after assisted reproductive technology.
        J Obstet Gynaecol Can. 2006; 28: 220-233
        • Shevell T.
        • Malone F.D.
        • Vidaver J.
        • et al.
        Assisted reproductive technology and pregnancy outcome.
        Obstet Gynecol. 2005; 106: 1039-1045
        • Middleton P.
        • Shepherd E.
        • Flenady V.
        • et al.
        Planned early birth versus expectant management (waiting) for prelabour rupture of membranes at term (37 weeks or more).
        Cochrane Database Syst Rev. 2017; 1: CD005302
        • Hannah M.E.
        • Ohlsson A.
        • Farine D.
        • et al.
        Induction of labor compared with expectant management for prelabor rupture of the membranes at term. Termprom study group.
        N Engl J Med. 1996; 334: 1005-1010
        • Pintucci A.
        • Meregalli V.
        • Colombo P.
        • et al.
        Premature rupture of membranes at term in low risk women: how long should we wait in the “latent phase”?.
        J Perinat Med. 2014; 42: 189-196
        • Pourali L.
        • Saghafi N.
        • Eslami Hasan Abadi S.
        • et al.
        Induction of labour in term premature rupture of membranes; oxytocin versus sublingual misoprostol; a randomised clinical trial.
        J Obstet Gynaecol. 2018; 38: 167-171
        • Lin M.G.
        • Nuthalapaty F.S.
        • Carver A.R.
        • et al.
        Misoprostol for labor induction in women with term premature rupture of membranes: a meta-analysis.
        Obstet Gynecol. 2005; 106: 593-601
        • Zeteroğlu S.
        • Engin-Ustün Y.
        • Ustün Y.
        • et al.
        A prospective randomized study comparing misoprostol and oxytocin for premature rupture of membranes at term.
        J Matern Fetal Neonatal Med. 2006; 19: 283-287
        • National Institute for Health and Care Excellence
        Inducing labour. NICE Guideline [ng207].
        (Available at:) (Accessed on August 26, 2022)
        • McCoy J.
        • Downes K.L.
        • Srinivas S.K.
        • et al.
        Postdates induction with an unfavorable cervix and risk of cesarean.
        J Matern Fetal Neonatal Med. 2019; 32: 2874-2878
        • Laughon S.K.
        • Zhang J.
        • Troendle J.
        • et al.
        Using a simplified Bishop score to predict vaginal delivery.
        Obstet Gynecol. 2011; 117: 805-811
        • Crane J.M.
        Factors predicting labor induction success: a critical analysis.
        Clin Obstet Gynecol. 2006; 49: 573-584
        • Peregrine E.
        • O'Brien P.
        • Omar R.
        • et al.
        Clinical and ultrasound parameters to predict the risk of cesarean delivery after induction of labor.
        Obstet Gynecol. 2006; 107: 227-233
        • Hatfield A.S.
        • Sanchez-Ramos L.
        • Kaunitz A.M.
        Sonographic cervical assessment to predict the success of labor induction: a systematic review with metaanalysis.
        Am J Obstet Gynecol. 2007; 197: 186-192
        • Lydon-Rochelle M.T.
        • Cárdenas V.
        • Nelson J.C.
        • et al.
        Induction of labor in the absence of standard medical indications: incidence and correlates.
        Med Care. 2007; 45: 505-512
        • Le Ray C.
        • Carayol M.
        • Bréart G.
        • et al.
        Elective induction of labor: failure to follow guidelines and risk of cesarean delivery.
        Acta Obstet Gynecol Scand. 2007; 86: 657-665
        • Oshiro B.T.
        • Henry E.
        • Wilson J.
        • et al.
        Decreasing elective deliveries before 39 weeks of gestation in an integrated health care system.
        Obstet Gynecol. 2009; 113: 804-811
        • Fisch J.M.
        • English D.
        • Pedaline S.
        • et al.
        Labor induction process improvement: a patient quality-of-care initiative.
        Obstet Gynecol. 2009; 113: 797-803
        • Reisner D.P.
        • Wallin T.K.
        • Zingheim R.W.
        • et al.
        Reduction of elective inductions in a large community hospital.
        Am J Obstet Gynecol. 2009; 200: 674.e1-674.e7
        • Main E.K.
        • Chang S.C.
        • Cheng Y.W.
        • et al.
        Hospital-level variation in the frequency of cesarean delivery among nulliparous women who undergo labor induction.
        Obstet Gynecol. 2020; 136: 1179-1189
        • Coonrod D.V.
        • Drachman D.
        • Hobson P.
        • et al.
        Nulliparous term singleton vertex cesarean delivery rates: institutional and individual level predictors.
        Am J Obstet Gynecol. 2008; 198 (discussion e11): 694.e1-694.e11
        • Brennan D.J.
        • Robson M.S.
        • Murphy M.
        • et al.
        Comparative analysis of international cesarean delivery rates using 10-group classification identifies significant variation in spontaneous labor.
        Am J Obstet Gynecol. 2009; 201: 308.e1-308.e8