Infertility, FemalePhase 4LEFTNCT04002635
Letrozole for Frozen Embryo Transfer (FET) in Patients With Polycystic Ovary Syndrome (PCOS)
A Phase 4 study testing Letrozole and estradiol valerate in people with Infertility, Female and Polycystic Ovary Syndrome, run by CRG UZ Brussel.
Trial summary
To offer patients with oligomenorrhoea or amenorrhoea an alternative to frozen embryo transfer in an artificial cycle, endometrial preparation using letrozole may be a valuable option. Read more about this study
- Who is it for?
- Ages 18 to 40 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Infertility, Female, Polycystic Ovary Syndrome, IVF
- What is being tested?
- Letrozole and estradiol valerate
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 0 participants
- Where
- No sites listed yet
- Study dates
- 1 Dec 2020to 1 Apr 2022
- Phase
- Phase 4
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age more than or equal to 18 and less than or equal to 40
- BMI more than or equal to 18 and less than or equal to 35
- Diagnosis of PCOS according to Rotterdam criteria
- Normal gynaecological ultrasound < 6 months before inclusion
- Signed informed consent form
- Day 5 or 6 frozen-thawed embryo transfer, blastocyst stage
Who cannot join
- Recurrent implantation failure
- Recurrent miscarriage
- Presence of adenomyosis
- Untreated intrauterine pathology
- rAFS (revised American Fertility Society) Grade III or IV endometriosis
- Hydrosalpinx
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- In vitro maturation (IVM)
- Untreated autoimmune disorders
- (History of) malignancy
- Allergy or reaction to the use of progynova, utrogestan and/or letrozole in the past
- Pre-implantation genetic testing (PGT)
About this study
Official title: Endometrial Preparation Using Letrozole Compared to Artificial Cycle for Frozen Embryo Transfer in PCOS Patients
To offer patients with oligomenorrhoea or amenorrhoea an alternative to frozen embryo transfer in an artificial cycle, endometrial preparation using letrozole may be a valuable option. Letrozole, a potent, reversible nonsteroidal aromatase inhibitor with relatively short half-life, can successfully induce ovulation without any adverse anti-estrogenic effects and thus without affecting the endometrium. The use of letrozole typically results in monofollicular growth and this reduces the effect of supraphysiological levels of estrogen on the endometrium and embryo. The purpose of this study is to compare a frozen-thawed embryo transfer in an artificial cycle with a letrozole-induced ovulatory cycle, specifically in PCOS patients. The primary outcome is early pregnancy loss.
- Being tested
- Letrozole, estradiol valerate
- Keywords
- frozen embryo transfer
- Medical subject headings
- Infertility, Female, Polycystic Ovary Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LetrozoleDrug
Letrozole ovulation induction
estradiol valerateDrug
Also called progesterone
hormonal replacement therapy
| Study group | Role | What they receive |
|---|---|---|
| Hormonal Replacement Therapy | Active comparator | Artificial preparation of the endometrium using estradiol valerate 2mg 3x/day, and vaginal micronized progesterone 2x 400mg/day. Receives: Drug: estradiol valerate |
| Letrozole | Experimental | Using letrozole for ovulation induction before planning the frozen embryo transfer Receives: Drug: Letrozole |
What is being measured
The primary outcome is the main question the study is designed to answer.
early pregnancy loss
Measured: 12 weeks after frozen embryo transfer
Secondary outcomes (9)
cancellation rate
Measured: 2 months
number of visits to the clinic
Measured: 2 months
endometrial thickness on the day of planning of FET
Measured: 1 day
implantation rate
Measured: 1 day
biochemical and clinical pregnancy rate
Measured: 12 weeks
live birth rate
Measured: 1 year
neonatal birth weight
Measured: 1 year
term of delivery
Measured: 1 year
hypertensive disorders of pregnancy
Measured: 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jun 2019
- Study start1 Dec 2020 (estimated)
- Primary completion1 Apr 2021 (estimated)
- Study completion1 Apr 2022 (estimated)
Why it stopped: Practical issues
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Infertility, FemaleStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- CRG UZ Brussel
- Sponsor type
- University, hospital or other
- Collaborators
- University Hospital, Ghent
- Responsible party
- Principal investigator, Liese Boudry, CRG UZ Brussel
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04002635
- Sponsor's protocol ID
- 2019LEFT001
- Acronym
- LEFT
- Status last verified
- Jan 2021
- First submitted
- 27 Jun 2019
- Last updated
- 8 Jan 2021
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Sharing with other study site, UZ Gent
Study at a glance
From the registry record, last updated by the sponsor on 8 Jan 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Endometrial Preparation Using Letrozole Compared to Artificial Cycle for Frozen Embryo Transfer in PCOS Patients
- ClinicalTrials.gov ID
- NCT04002635
- Acronym / sponsor ID
- LEFT / 2019LEFT001
- Keywords
- frozen embryo transfer
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- WithdrawnReason stopped: Practical issues
- Enrolment
- 0 participants (actual)
- Lead sponsor
- CRG UZ BrusselUniversity, hospital or other
- Collaborators
- University Hospital, Ghent
- Study start
- 1 Dec 2020 (estimated)
- Primary completion
- 1 Apr 2021 (estimated)
- Study completion
- 1 Apr 2022 (estimated)
- First posted
- 28 Jun 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To offer patients with oligomenorrhoea or amenorrhoea an alternative to frozen embryo transfer in an artificial cycle, endometrial preparation using letrozole may be a valuable option. Letrozole, a potent, reversible nonsteroidal aromatase inhibitor with relatively short half-life, can successfully induce ovulation without any adverse anti-estrogenic effects and thus without affecting the endometrium. The use of letrozole typically results in monofollicular growth and this reduces the effect of supraphysiological levels of estrogen on the endometrium and embryo. The purpose of this study is to compare a frozen-thawed embryo transfer in an artificial cycle with a letrozole-induced ovulatory cycle, specifically in PCOS patients. The primary outcome is early pregnancy loss.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Hormonal Replacement Therapy | Active comparator | Drug: estradiol valerateArtificial preparation of the endometrium using estradiol valerate 2mg 3x/day, and vaginal micronized progesterone 2x 400mg/day. |
| Letrozole | Experimental | Drug: LetrozoleUsing letrozole for ovulation induction before planning the frozen embryo transfer |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Age more than or equal to 18 and less than or equal to 40
- BMI more than or equal to 18 and less than or equal to 35
- Diagnosis of PCOS according to Rotterdam criteria
- Normal gynaecological ultrasound < 6 months before inclusion
- Signed informed consent form
Key exclusion criteria (11 listed)
- Recurrent implantation failure
- Recurrent miscarriage
- Presence of adenomyosis
- Untreated intrauterine pathology
- rAFS (revised American Fertility Society) Grade III or IV endometriosis
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| LetrozoleLetrozole ovulation induction | Drug | Letrozole |
| estradiol valerateAlso: progesteronehormonal replacement therapy | Drug | Hormonal Replacement Therapy |
Primary outcome
early pregnancy loss
Time frame: 12 weeks after frozen embryo transfer
9 secondary outcomes
cancellation rate
Time frame: 2 months
number of visits to the clinic
Time frame: 2 months
endometrial thickness on the day of planning of FET
Time frame: 1 day
implantation rate
Time frame: 1 day
biochemical and clinical pregnancy rate
Time frame: 12 weeks
live birth rate
Time frame: 1 year
neonatal birth weight
Time frame: 1 year
term of delivery
Time frame: 1 year
hypertensive disorders of pregnancy
Time frame: 1 year
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Jan 2021.
- Individual participant dataSharing planned: Yes. Sharing with other study site, UZ Gent
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Letrozole and estradiol valerate in people with Infertility, Female and Polycystic Ovary Syndrome, run by CRG UZ Brussel.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 8 Jan 2021. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
early pregnancy loss (time frame: 12 weeks after frozen embryo transfer). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Jan 2021; AzTrials last refreshed its copy on 8 Nov 2026.