Summary
A report in the European Journal of Contraception & Reproductive Health Care concludes that DMPA may reverse the effects of mifepristone when used for medication abortions. The purpose of the report was to evaluate outcomes in patients who did and did not receive DMPA concurrently with mifepristone for mifepristone-misoprostol abortion and estimate the impact of DMPA on mifepristone action.
Depot-MedroxyProgesterone Acetate (DMPA) is a long-acting, injectable, synthetic compound designed to mimic the effects of progesterone. It is a commonly used contraceptive method. A widely known DMPA brand name is Depo-Provera.
Natural, oral progesterone and synthetic DMPA are pharmacologically different. Thus the results from this study do not directly apply to abortion pill reversal therapy (APR). However, the conclusion that “DMPA may impact mifepristone variably by gestational duration” is consistent with results from APR studies.
Materials and Methods
In this secondary analysis of a retrospective study, the authors analysed treatment failure and continuing pregnancy as a reason for failure both overall and by gestational duration group. They assessed available literature to estimate that misoprostol alone would result in abortion in approximately 74% of pregnancies without mifepristone and calculated the impact of adding mifepristone to the treatment regimen and of DMPA on these outcomes.
Conclusion
The report concluded that ongoing pregnancy as the reason for medication abortion failure occurs more frequently with advancing gestation in patients that do and do not receive DMPA concurrently with mifepristone. They also concluded that DMPA may impact mifepristone variably by gestational duration, but larger studies are needed.
Results
More than half of the patients in each group had pregnancies ≤49 days gestation (no DMPA: 432/704 [61.4%]; DMPA 73/141 [51.8%], p = 0.04). Ongoing pregnancy rates increased with advancing gestational duration both with (p = 0.0005) and without (p = 0.04) concomitant DMPA administration. The authors state that “no individual gestational duration group demonstrated a significant difference in outcomes between patients that did and did not receive DMPA, likely because of small numbers in each group.” However their data shows that the ongoing pregnancy rate for gestational duration group 50-56 days was 8.33%, for patients receiving DMPA, but only .67%, for patients that did not receive DMPA. That is a difference of 1140%.
Concomitant DMPA with mifepristone increased the likelihood of an ongoing pregnancy as a percentage of the expected rate if DMPA completely blocked all mifepristone action by 25.3% for all gestational ages and 16.1% for gestational ages ≤49 days. The authors did not document the ongoing pregnancy rate for gestational duration groups 50-56, 57-63, and 64-70 days. The chart above provides that information using the author’s data and the calculation method they define in Appendix 1.
Click here to view the spreadsheet that performs the calculations for the chart above.
Citation
Creinin, Mitchell D., and Christy M. Boraas. 2025. “Depomedroxyprogesterone Acetate Impact on Mifepristone Action during Medication Abortion.” The European Journal of Contraception & Reproductive Health Care, May, 1–5. https://doi.org/10.1080/13625187.2025.2495601.
Further Reading
Additional mifepristone, progesterone, and abortion pill reversal studies can be found here https://aprscience.org/studies/.