Does BMI Affect Vag Miso Cervical Ripening? (IMPROVE Subanalysis)

The ACOG 2025 guideline specifically recommends either oral or vaginal misoprostol for cervical ripening; it does not include buccal administration among its endorsed routes. With the rising rates of both obesity and labor induction, understanding the optimal agents for induction in obese patients is crucial. In a new study released ahead of print on March 4, 2026, in the AJOG, investigators from Indianapolis released findings from a secondary analysis of the IMPROVE trial (2019, AJOG) looking at the effect of obesity on buccal vs vaginal doses of misoprostol for cervical ripening. Listen in for details. 1. Haas DM, Daggy J, Flannery KM, Dorr ML, Bonsack C, Bhamidipalli SS, Pierson RC, Lathrop A, Towns R, Ngo N, Head A, Morgan S, Quinney SK. A comparison of vaginal versus buccal misoprostol for cervical ripening in women for labor induction at term (the IMPROVE trial): a triple-masked randomized controlled trial. Am J Obstet Gynecol. 2019 Sep;221(3):259.e1-259.e16. doi: 10.1016/j.ajog.2019.04.037. Epub 2019 May 7. PMID: 31075246; PMCID: PMC7692024. 2. ACOG July 2025: Cervical Ripening in Pregnancy, ACOG Clinical Practice Guideline No. 9 3. Bynarowicz, Taylor M. et al. The impact of body mass index on misoprostol dosing for labor induction: a comparison of vaginal and buccal dosage forms American Journal of Obstetrics & Gynecology, Volume 0, Issue 0: https://www.ajog.org/article/S0002-9378(26)00126-2/fulltext 4. Etrusco A, Sfregola G, Zendoli F, et al. Effect of Maternal Age and Body Mass Index on Induction of Labor Using Oral Misoprostol in Late-Term Pregnancies: A Retrospective Cross-Sectional Study. Gynecologic and Obstetric Investigation. 2024. 5. Prostaglandin Versus Mechanical Dilation and the Effect of Maternal Obesity on Failure to Achieve Active Labor: A Cohort Study. 6. Beckwith L, Magner K, Kritzer S, Warshak CR. The Journal of Maternal-Fetal & Neonatal Medicine : The Official Journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. 2017.