Comparison of two doses of ulipristal acetate for medication abortion up to 63 days of gestation
| ISRCTN | ISRCTN40136678 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN40136678 |
| Secondary identifying numbers | 1060 |
- Submission date
- 27/08/2025
- Registration date
- 01/09/2025
- Last edited
- 05/09/2025
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Pregnancy and Childbirth
Plain English summary of protocol
Background and study aims
This study compares two different doses of ulipristal acetate when used with misoprostol to end early pregnancy of up to 63 days. Mifepristone plus misoprostol is the standard regimen for medication abortion, but mifepristone is not always available in Mexico. Ulipristal acetate is a potential alternative. The aim is to determine whether a lower dose of ulipristal acetate (30 mg) is as effective and safe as a higher dose (60 mg).
Who can participate?
Women aged 18 years or older (including emancipated minors) with an intrauterine pregnancy of up to 63 days, confirmed by ultrasound, who request a legal medication abortion in Mexico City and meet clinical eligibility criteria.
What does the study involve?
Participants are randomly assigned to receive either one 30 mg tablet of ulipristal acetate plus two placebo tablets, or two 30 mg tablets of ulipristal acetate plus one placebo tablet. All participants then take four 200 mcg tablets of misoprostol (800 mcg total) buccally at home 24 hours later. Follow-up takes place 7–10 days later and includes an ultrasound and an interview. The main outcomes assessed are treatment success without surgery or extra medication, safety, and participant satisfaction.
What are the possible benefits and risks of participating?
Participants may benefit from access to a safe and effective abortion regimen under close medical supervision. Risks include expected side effects of the medicines such as cramping, bleeding, nausea, vomiting, diarrhoea, chills, and fever. Serious side effects are uncommon but are monitored closely, and clinical care is provided if needed.
Where is the study run from?
The study is carried out in two maternity hospitals in Mexico City: Hospital Materno Infantil Inguarán and Hospital Materno Infantil Nicolás M. Cedillo.
When is the study starting and how long is it expected to run for?
December 2024 to March 2026
Who is funding the study?
The study is jointly funded by Gynuity Health Projects (New York, USA) and the Secretaría de Salud de la Ciudad de México (SEDESA).
Who is the main contact?
Manuel Bousiéguez, (Associate, Gynuity Health Projects), mbousieguez@gynuity.org
Contact information
Principal Investigator
215 Lexington Ave # 1702.
New York
10016
United States of America
 ORCID ID |
0000-0003-0876-0058 |
|---|---|
| Phone | +1.212.448.1230 |
| bwinikoff@gynuity.org |
Public, Scientific, Principal Investigator
Agricultura # 45 PH 4. Col. Escandón
Mexico City
11800
Mexico
| ORCID ID |
0000-0002-6511-2236 |
|---|---|
| Phone | +52 55 5418-6607 |
| mbousieguez@gynuity.org |
Principal Investigator
Parque Bosencheve número 2, interior 8, Colonia El Parque
Naucalpan
CP 53398
Mexico
| ORCID ID |
0009-0001-7632-2749 |
|---|---|
| Phone | +52 55 2300 1401 |
| martinezangelica995@gmail.com |
Study information
| Study design | Multicenter interventional double-blinded placebo-controlled parallel-group randomized trial |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised parallel trial |
| Study setting(s) | Hospital |
| Study type | Safety, Efficacy |
| Scientific title | Randomised, double-blind, placebo-controlled, parallel-group clinical trial to evaluate the efficacy of two regimens of ulipristal acetate in combination with misoprostol for medication abortion in women up to 63 days of gestation |
| Study acronym | ULI-60vs30 |
| Study objectives | Hypothesis: A 30 mg dose of ulipristal acetate, when combined with misoprostol, will have comparable efficacy, safety, and acceptability to the 60 mg dose for medication abortion up to 63 days of gestation. Primary objective: To compare the efficacy of 30 mg vs 60 mg of ulipristal acetate, followed by buccal misoprostol 800 mcg, for medication abortion. Secondary objectives: To assess the safety and acceptability of both regimens. |
| Ethics approval(s) |
Approved 18/08/2025, Research Ethics Committee, Belisario Domínguez Specialty Hospital (Av. Tláhuac No. 4866, esq. Zacatlán. Col. San Lorenzo Texcoco. Alcaldía Iztapalapa., Mexico City, 09790, Mexico; + 52 55 5850-0000 Ext. 1064; dgpcs.correspondencia@salud.cdmx.gob.mx), ref: 501-010-47-25 |
| Health condition(s) or problem(s) studied | Termination of pregnancy (medication abortion) in women up to 63 days of gestation; unintended pregnancy |
| Intervention | Intervention group (60 mg): Ulipristal acetate 60 mg orally (two 30 mg tablets) administered under direct supervision in clinic, followed 24 hours later by self-administered buccal misoprostol 800 mcg at home. Comparator group (30 mg): Ulipristal acetate 30 mg orally (one 30 mg tablet + two placebo tablets) administered under direct supervision in clinic, followed 24 hours later by self-administered buccal misoprostol 800 mcg at home. Placebo tablets are used to ensure identical appearance of study packages and maintain double blinding. Randomisation was performed using Stata 18 SE (StataCorp. 2023). A block randomisation scheme with a fixed block size of four was generated separately for each study site. The random number generator was initialised with a fixed seed (20250816) to ensure reproducibility. If enrolment exceeds initial projections at a site, the sequence can be extended by rerunning the program with an updated sample size; in such cases, all prior allocations remain identical to the original scheme, and new allocations are generated in continuation of the same random sequence. The random allocation lists will be used to prepare sequentially numbered, opaque envelopes containing the study medications. Participants will be enrolled sequentially and assigned the next available envelope corresponding to their site. |
| Intervention type | Drug |
| Pharmaceutical study type(s) | Dose response |
| Phase | Phase II/III |
| Drug / device / biological / vaccine name(s) | Ulipristal acetate, misoprostol |
| Primary outcome measure | 1. Efficacy — Complete abortion without need for surgical intervention or additional misoprostol measured by proportion of participants with successful medication abortion at follow-up visit (7–10 days after ulipristal administration) 2. Safety — Occurrence of serious adverse events attributable to the study drugs measured by number and proportion of participants with serious adverse events from ulipristal administration until end of follow-up (7–10 days or extended if needed) |
| Secondary outcome measures | Acceptability — Participant-reported satisfaction with the regimen (and willingness to recommend) measured by proportion rating experience as “satisfied/very satisfied” on structured exit interview (Form 3) at follow-up visit 7–10 days after ulipristal (or at extended follow-up, if applicable) |
| Overall study start date | 01/12/2024 |
| Completion date | 31/05/2026 |
Eligibility
| Participant type(s) | Patient, Service user |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 99 Years |
| Sex | Female |
| Target number of participants | 426 |
| Key inclusion criteria | 1. Women aged ≥18 years (or emancipated minors) 2. Intrauterine pregnancy confirmed by ultrasound 3. Gestational age ≤63 days by ultrasound 4. Eligible for medication abortion under standard clinical criteria 5. Resident in Mexico City 6. Access to a telephone for follow-up 7. Able and willing to provide written informed consent |
| Key exclusion criteria | 1. Liver or renal disease 2. Confirmed or suspected ectopic pregnancy, gestational trophoblastic disease, or undiagnosed adnexal mass 3. Intrauterine device (IUD) in situ 4. Known allergy to ulipristal acetate, misoprostol, or other prostaglandins 5. Unwilling or unable to attend follow-up visit 6. Unable to provide informed consent |
| Date of first enrolment | 01/10/2025 |
| Date of final enrolment | 31/03/2026 |
Locations
Countries of recruitment
- Mexico
Study participating centres
Mexico City
15310
Mexico
Mexico City
02420
Mexico
Sponsor information
Research organisation
215 Lexington Ave # 1702.
New York
10016
United States of America
| Phone | +1.212.448.1230 |
|---|---|
| bwinikoff@gynuity.org | |
| Website | https://gynuity.org |
"ROR" |
https://ror.org/00swp5c87 |
Funders
Funder type
Charity
No information available
Results and Publications
| Intention to publish date | 30/09/2026 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | The results of this study will first be shared with the research team and with health authorities of the Secretaría de Salud de la Ciudad de México (SEDESA). Findings will then be presented to relevant stakeholders, including policymakers, clinicians, and representatives of organisations involved in sexual and reproductive health. Results are expected to be disseminated through presentations at national and international scientific conferences and through publication in peer-reviewed scientific journals. A summary of the results will also be uploaded to the clinical trial registry record after completion of the study. |
| IPD sharing plan | Anonymised individual participant data (IPD) will be made available after publication of the main study results in a peer-reviewed journal. Data will include a de-identified dataset and a variable dictionary. Access will be provided only to qualified researchers who submit a formal request, commit to using the data responsibly, protect participant confidentiality, and obtain ethics approval or exemption where applicable. Approval of data sharing requests will be decided by the principal investigators. |
Editorial Notes
05/09/2025: Contact details updated.
03/09/2025: The following changes were made:
1. The secondary identifying number 1043 was replaced with 1060.
2. An additional contact was added.
28/08/2025: Trial's existence confirmed by Ciudad de Mexico.
