Abortion pills are highly effective throughout pregnancy.
In the first trimester, success rates are approximately 99% when using both mifepristone and misoprostol. Misoprostol alone is also very effective, with success rates ranging from 94-97%.
Sources
- World Health Organization. 2023. Clinical Practice Handbook for Quality Abortion Care. https://www.who.int/publications/i/item/9789240075207
- Morris, Jessica L., Beverly Winikoff, Rasha Dabash, Andrew Weeks, Anibal Faundes, Kristina Gemzell-Danielsson, Nathalie Kapp, et al. 2017. ‘FIGO’s Updated Recommendations for Misoprostol Used Alone in Gynecology and Obstetrics’. International Journal of Gynecology and Obstetrics 138 (3): 363–66. https://doi.org/10.1002/ijgo.12181.
- Lerma, Klaira, and Paul D. Blumenthal. 2020. ‘Current and Potential Methods for Second Trimester Abortion’. Best Practice and Research: Clinical Obstetrics and Gynaecology 63:24–36. https://doi.org/10.1016/j.bpobgyn.2019.05.006
- Lui, Man Wa, and Pak Chung Ho. 2020. ‘First Trimester Termination of Pregnancy’. Best Practice and Research: Clinical Obstetrics and Gynaecology 63:13–23. https://doi.org/10.1016/j.bpobgyn.2019.06.004
- Raymond, Elizabeth G., Caitlin Shannon, Mark A. Weaver, and Beverly Winikoff. 2013. ‘First-Trimester Medical Abortion with Mifepristone 200 Mg and Misoprostol: A Systematic Review’. Contraception 87 (1): 26–37. https://doi.org/10.1016/j.contraception.2012.06.011
- Kapp, Nathalie, Elisabeth Eckersberger, Antonella Lavelanet, and Maria Isabel Rodriguez. 2019. ‘Medical Abortion in the Late First Trimester: A Systematic Review’. Contraception 99 (2): 77–86.
- Raymond, Elizabeth G., Mark A. Weaver, and Tara Shochet. 2023. ‘Effectiveness and Safety of Misoprostol-Only for First-Trimester Medication Abortion: An Updated Systematic Review and Meta-Analysis’. Contraception 127 (November):110132. https://doi.org/10.1016/j.contraception.2023.110132.
- Moseson, Heidi, Ruvani Jayaweera, Ijeoma Egwuatu, Belén Grosso, Ika Ayu Kristianingrum, Sybil Nmezi, Ruth Zurbriggen, et al. 2021. ‘Effectiveness of Self-Managed Medication Abortion with Accompaniment Support in Argentina and Nigeria (SAFE): A Prospective, Observational Cohort Study and Non-Inferiority Analysis with Historical Controls’. The Lancet Global Health, no. 21, 1–9. https://doi.org/10.1016/s2214-109x(21)00461-7
