TerminatedNCT03774745Updated Jan 22, 2020Results posted

Blocking Mifepristone Action With Progesterone

A Phase 1/2 interventional study of Mifepristone 200 MG and micronized Progesterone in Pregnancy, Unwanted, sponsored by University of California, Davis. Terminated at 3 sites in United States. Open to female participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2020-01-22.

Sponsored by University of California, Davis · Phase 1/2, Interventional, and Treatment

Why this study was terminated

Safety

Phase: Phase 1/2
Study type: Interventional
Enrollment: 12
Allocation: Randomized
Ages: 18 Years and older
Sex: Female

Study summary

Double-blind randomized trial to evaluate the potential impact of progesterone treatment on early pregnancies exposed to mifepristone.

Read the detailed description

Medical abortion commonly refers to early pregnancy termination (usually before 10 weeks' gestation) performed without primary surgical intervention and resulting from the use of abortion-inducing medications. The use of medications to cause abortion has been around for almost 70 years but the modern era of medical abortion treatment evolved with the development of mifepristone, a progesterone-receptor blocker with an affinity for the receptor greater than progesterone itself.

Medical abortion with mifepristone and misoprostol is highly effective; however, the risk of continuing pregnancy is still present, especially as gestation advances. While most women opt for further treatment in these scenarios, such as surgical aspiration, there are some who decide to continue the pregnancy. Thus, even following treatment, some women do change their mind.

No well-done study has evaluated whether such treatment works. Poorly controlled case series are not evidence and systematic reviews of continuing pregnancy rates after mifepristone/prostaglandin analogue treatment failure do not reflect real life outcomes. This study is also a first step to understanding if large studies evaluating mifepristone antagonization with high-dose progesterone are indicated and if placebo-controlled randomized trials can be successfully completed when evaluating this question.

Conditions studied

Pregnancy, Unwanted

Keywords

mifepristone
progesterone
abortion

In context

Lead sponsor

University of California, Davis is the lead sponsor of 798 studies on the registry; 146 are open to participants now.

Of its 65 completed or terminated interventional studies of FDA-regulated products, 43 (66%) have results posted.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 18 Years and older
Sexes eligible: Female
Accepts healthy volunteers: Yes

Inclusion criteria

Pregnant females 18 years and older at enrollment.
Seeking surgical abortion at 44-63 days' gestation on Study day 1.
Have received counseling and signed informed consent per UCD standard procedures for surgical abortion.
Presence of embryonic gestational cardiac activity on transvaginal ultrasonography.
English-speaking
Willing to sign informed consent and follow study protocol.
Willing to experience potential expulsion of the pregnancy with mifepristone treatment.

Exclusion criteria

Exclusion Criteria:

Medical contraindications to medical abortion.
1. Poorly controlled hypertension (systolic BP >160 or diastolic BP >95)
2. Significant anemia - known recent hemoglobin \<9.5 gm/dL
3. Clinically significant cardiovascular disease (angina, valvular disease, arrhythmia, or congestive heart failure)
4. Breastfeeding
5. Coagulopathy or therapeutic coagulation
6. Ultrasound evidence of molar or ectopic pregnancy
7. Chronic systemic corticosteroid use
8. Adrenal disease
9. Sickle cell anemia with frequent/recent crises
10. Glaucoma
IUD in place during conception, even if removed.
Peanut allergy.
Known intolerance of mifepristone or progesterone.
Any other condition, that in the opinion of the clinician, would contraindicate mifepristone, progesterone or medical abortion.

Study design

Phase: Phase 1 / Phase 2
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel assignment
Masking: Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment: 12 participants (actual)

Study arms

Experimental
Progesterone
Micronized progesterone 200mg oral capsules starting 24 hours after mifepristone 200mg ingestion (day 1). Progesterone treatment days 2-4: two capsules twice daily orally. Progesterone treatment days 5-15, 16 or 17: two capsules once daily orally.
Drug: Mifepristone 200 MG · Drug: micronized Progesterone
Placebo comparator
Placebo oral capsule
Placebo capsules starting 24 hours after mifepristone 200mg ingestion (day 1). Placebo treatment days 2-4: two capsules twice daily orally. Placebo treatment days 5-15, 16 or 17: two capsules once daily orally.
Drug: Mifepristone 200 MG · Drug: Placebo oral capsule

Interventions

DrugMifepristone 200 MG
All subjects receive mifepristone tablet on treatment day 1.
Also known as: Mifeprex
Drugmicronized Progesterone
Subjects randomized to progesterone receive treatment starting day 2.
Also known as: Prometrium
DrugPlacebo oral capsule
Subjects randomized to placebo receive treatment starting day 2.
Also known as: Placebo (for micronized progesterone)

What researchers measure

Primary outcomes

Continuing Pregnancy Based on Ultrasound Examination
Pregnancy still in uterus with normal growth and gestational cardiac activity present based on ultrasound examination
Time frame: at 14-16 days after mifepristone administration

Secondary outcomes

Expulsion During Follow-up Evaluation
Pregnancy expulsion following mifepristone treatment
Time frame: up to 16 days after mifepristone administration
Number of Participants With Adverse Events During Follow-up Evaluation
Side effects from progesterone/placebo treatment and ability to continued treatment as prescribed
Time frame: up to 16 days after mifepristone administration
Medical Safety During Treatment and Follow-up
Adverse events related to morbidity, e.g. hemorrhage, emergency department visits, emergent dilation and curettage procedures
Time frame: up to 16 days after mifepristone administration
Number of Participants With Change in Serum Progesterone and hCG During Follow-up
Change in serum progesterone and hCG during follow-up evaluation
Time frame: up to 16 days after mifepristone administration

Results

Posted Jan 22, 2020

Limitations and caveats

Early termination for safety reasons leading to small numbers of subjects analyzed for efficacy outcomes. Imbalance in participant characteristics due to early termination.

Participant flow

Participant flow — Overall Study
Milestone	Progesterone	Placebo Oral Capsule
Started	6	6
Follow-up 1	5	6
Follow-up 2	4	2
Completed	4	2
Not completed	2	4

Outcome measures

PrimaryContinuing Pregnancy Based on Ultrasound Examination

Pregnancy still in uterus with normal growth and gestational cardiac activity present based on ultrasound examination

Time frame:: at 14-16 days after mifepristone administration
Reported as:: Count of participants · Participants

Continuing Pregnancy Based on Ultrasound Examination
Participants	Progesterone	Placebo Oral Capsule
Continuing Pregnancy Based on Ultrasound Examination	4	2

SecondaryExpulsion During Follow-up Evaluation

Pregnancy expulsion following mifepristone treatment

Time frame:: up to 16 days after mifepristone administration
Reported as:: Count of participants · Participants

Expulsion During Follow-up Evaluation
Participants	Progesterone	Placebo Oral Capsule
Expulsion During Follow-up Evaluation	1	2

SecondaryNumber of Participants With Adverse Events During Follow-up Evaluation

Side effects from progesterone/placebo treatment and ability to continued treatment as prescribed

Time frame:: up to 16 days after mifepristone administration
Reported as:: Number · participants

Number of Participants With Adverse Events During Follow-up Evaluation
participants	Progesterone	Placebo Oral Capsule
Nausea	2	1
Vomiting	2	0
Mastalgia	0	0
Tiredness	0	1
Mood changes	1	0
Reflux	0	0
Dizziness	0	0
Bleeding	1	3
Spotting	0	0
Cramping	0	0

SecondaryMedical Safety During Treatment and Follow-up

Adverse events related to morbidity, e.g. hemorrhage, emergency department visits, emergent dilation and curettage procedures

Time frame:: up to 16 days after mifepristone administration
Reported as:: Number · participants

Medical Safety During Treatment and Follow-up
participants	Progesterone	Placebo Oral Capsule
Hemorrhage	1	2
Emergency Room Visit	1	2
Transfusion	0	1
Emergent D&C	0	2
Side effects - request D&C	1	1

SecondaryNumber of Participants With Change in Serum Progesterone and hCG During Follow-up

Change in serum progesterone and hCG during follow-up evaluation

Time frame:: up to 16 days after mifepristone administration
Reported as:: Number · participants

Number of Participants With Change in Serum Progesterone and hCG During Follow-up
participants	Progesterone	Placebo Oral Capsule
Progesterone increase from baseline at FU 1	5	2
Progesterone decrease from baseline at FU 1	0	2
hCG increase from baseline at FU 1	4	3
hCG decrease from baseline at FU 1	1	3

Adverse events

Collected over Two weeks. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
Group	Deaths	Serious	Other
Progesterone	0/6 (0%)	1/6 (16.7%)	1/6 (16.7%)
Placebo Oral Capsule	0/6 (0%)	2/6 (33.3%)	1/6 (16.7%)

Most frequent serious events

Most frequent serious events
Event	Progesterone	Placebo Oral Capsule
HemorrhagePregnancy, puerperium and perinatal conditions	1/6	2/6
Emergency D&CPregnancy, puerperium and perinatal conditions	0/6	2/6
Emergency Room VisitPregnancy, puerperium and perinatal conditions	1/6	2/6
TransfusionPregnancy, puerperium and perinatal conditions	0/6	1/6

Most frequent other events

Most frequent other events
Event	Progesterone	Placebo Oral Capsule
Side effects requesting study discontinuationPregnancy, puerperium and perinatal conditions	1/6	1/6

Baseline characteristics

Intended to enroll 40 total - study stopped after 12 enrolled due to safety concerns

Age, Continuous
Age, Continuous(years)	Progesterone	Placebo Oral Capsule	Total
Median	29.8 (24.6 to 39.6)	24.1 (20.9 to 33.8)	27.3 (20.9 to 39.6)

Sex: Female, Male
Sex: Female, Male(Participants)	Progesterone	Placebo Oral Capsule	Total
Female	6	6	12
Male	0	0	0

Ethnicity (NIH/OMB)
Ethnicity (NIH/OMB)(Participants)	Progesterone	Placebo Oral Capsule	Total
Hispanic or Latino	1	1	2
Not Hispanic or Latino	5	5	10
Unknown or Not Reported	0	0	0

Race (NIH/OMB)
Race (NIH/OMB)(Participants)	Progesterone	Placebo Oral Capsule	Total
American Indian or Alaska Native	0	0	0
Asian	2	2	4
Native Hawaiian or Other Pacific Islander	0	0	0
Black or African American	4	1	5
White	0	3	3
More than one race	0	0	0
Unknown or Not Reported	0	0	0

Region of Enrollment
Region of Enrollment(Participants)	Progesterone	Placebo Oral Capsule	Total
United States	6	6	12

Gestational Age
Gestational Age(days)	Progesterone	Placebo Oral Capsule	Total
Median	49.5 (47 to 56)	55 (48 to 61)	52.5 (47 to 61)

BMI
BMI(kg/m^2)	Progesterone	Placebo Oral Capsule	Total
Median	24.8 (19.0 to 36.4)	24.6 (22.7 to 52.3)	24.6 (19.0 to 52.3)

Obesity
Obesity(Participants)	Progesterone	Placebo Oral Capsule	Total
Count of participants	2	2	4

4 further baseline measures are reported on the registry.

Study locations

3 sites

Planned Parenthood Mar Monte
Sacramento, California 95816, United States
University of California, Davis
Sacramento, California 95817, United States
Family Planning Associates
Sacramento, California 95825, United States

References and documents

Publications

Creinin MD, Hou MY, Dalton L, Steward R, Chen MJ. Mifepristone Antagonization With Progesterone to Prevent Medical Abortion: A Randomized Controlled Trial. Obstet Gynecol. 2020 Jan;135(1):158-165. doi: 10.1097/AOG.0000000000003620. PubMed 31809439 ↗

Study documents

Protocol and statistical analysis plan · Jul 18, 2019

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No — Sharing de-identified data will be considered upon individual request

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Jan 22, 2020, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT03774745
Lead sponsor: University of California, Davis
Collaborators: Society of Family Planning
Responsible party: Sponsor
First posted: Dec 13, 2018
Start date: Feb 11, 2019
Primary completion: Jul 29, 2019
Completion: Aug 15, 2019
Results posted: Jan 22, 2020
Last update: Jan 22, 2020

Study contacts

Mitchell D Creinin, MD

principal investigator · University of California, Davis

Oversight

Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

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This study is terminated, as verified in Jan 2020. You cannot join it, but the record below documents what was studied.

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