Characteristics of studies included in a systematic review of abortion reversal
| Authors (year) | Study type | Population | Intervention | Comparison | Outcome |
| Delgado & Davenport28 (2012) | Case series | US women who took mifepristone for abortion and were interested in reversing effect; pelvic ultrasound performed prior to initiating treatment in at least 5/7; mifepristone dose unspecified | Treatment with progesterone (various regimens)* | None | Proportion of ongoing pregnancies – assessed via patient history (timing of assessment not specified) †Secondary outcomes: none |
| Garratt & Turner30 (2017) | Case series | Women in Australia who took mifepristone and were interested in reversing effect; pelvic ultrasound not performed prior to initiating treatment; mifepristone dose unspecified | Vaginal progesterone for 2 weeks: 400 mg twice daily for 3 days, then 400 mg nightly for 6 days, then 200 mg nightly for 6 days | None | Proportion of ongoing pregnancies – assessed via ultrasound and patient history (timing of assessment varied) †Secondary outcomes: none |
| Delgado et al 29 (2018) | Case series | Pregnant women in US and several other countries who had taken mifepristone but not misoprostol and were interested in reversing effects; 72 hours or less after taking mifepristone; mifepristone dose unspecified | Various progesterone dosing/formulations: high-dose oral, intramuscular (various doses and frequencies), oral caps, vaginal suppository | None | Proportion of ongoing pregnancies – assessed via patient history (timing of assessment not specified) †Secondary outcomes: incidence of birth defects |
| Creinin et al 31 (2020) | Double-blind, randomised, placebo-controlled trial | Patients at 44–63 days of gestation with confirmed cardiac activity who were planning surgical abortion | Mifepristone 200 mg, followed 24 hours later by oral progesterone 400 mg - twice daily for 3 days, then once daily until planned surgical abortion 14–16 days after enrollment | Mifepristone 200 mg followed by placebo | Proportion of ongoing pregnancies at 2 weeks – assessed via ultrasonography †Secondary outcomes: complications and side effects |
*See individual cases in table 2 for details on treatment regimens.
†Secondary outcomes: our secondary outcomes of interest were treatment side effects and complications (including bleeding, surgical intervention and gastrointestinal side effects) and birth defects.