InfertilityPhase 4LIFTNCT07508657
Progesterone Supplementation After Letrozole-stimulated Insemination
A Phase 4 study testing Progesterone in people with Infertility, run by Kirstine Kirkegaard at 4 sites in Denmark.
Trial summary
This trial aims to investigate whether luteal phase support improves the chance of pregnancy in women undergoing intrauterine insemination (IUI) following ovarian stimulation with letrozole. Read more about this study
- Who is it for?
- Ages 18 to 37 years, women only
- Conditions the study is for
- Infertility
- What is being tested?
- Progesterone
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 690 participants
- Where
- 4 sitesDenmark
- Study dates
- 28 Aug 2026to Jan 2030
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
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 37 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Age 18-37 years
- Scheduled for IUI with homologous or donor sperm
- Undergoing mild ovarian stimulation with letrozole
- Ability to provide written informed consent
Who cannot join
- Age > 37 years
- Anovulation due to hypogonadotropic hypogonadism
- Known hypersensitivity to progesterone or hard fat listed as an excipient in the Summary of Product Characteristics (SmPC) for Cyclogest.
- Known or suspected progesterone-sensitive malignant tumours
- Porphyria
- Known missed abortion or ectopic pregnancy
Show all 9Show fewer
- Active arterial or venous thromboembolism, severe thrombophlebitis, or a history of these conditions
- Severe hepatic dysfunction or liver disease
- Inability to speak or understand Danish sufficiently to comprehend oral and written study information
Trial locations and contacts
4 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Denmark4 sites, 4 recruiting
- Not yet recruiting
Copenhagen University Hospital - Rigshospitalet. Department of Gynecology, Fertility and Obstetrics
Copenhagen, 2100
Kristine Løssl, Clinical Associate Professor, +4535451077, fertilitet.rigshospitalet@regionh.dk
Kristine Løssl, Clinical Associate Professor
- Not yet recruiting
The Fertility Clinic, Herlev Hospital
Herlev, 2730
Maria Birkvad Rasmussen, Clinical Associate Professor, +4538683868, HEH-gynaekologisk-obstetrisk.afdeling.g@regionh.dk
Maria Birkvad Rasmussen, Clinical Associate Professor
- Recruiting
University Clinic for Fertility, Horsens Regional Hospital, Central Denmark Region
Horsens, 8700
Kirstine Kirkegaard, Clinical Associate Professor, +4578426562, fertilitet@horsens.rm.dk
Kirstine Kirkegaard, Clinical Associate Professor
- Not yet recruiting
The Fertility Clinic, Hvidovre Hospital
Hvidovre, 2650
Nina la Cour Freiesleben, Clinical Associate Professor, +4538622744, fertilitetsklinikken.amager-og-hvidovre-hospital@regionh.dk
Nina la Cour Freiesleben, Clinical Associate Professor
About this study
Official title: Luteal Phase Support Following Letrozole Treatment in Women Undergoing Intrauterine Insemination: a Multicenter Randomized Trial
This trial aims to investigate whether luteal phase support improves the chance of pregnancy in women undergoing intrauterine insemination (IUI) following ovarian stimulation with letrozole.
In this randomized clinical trial, 690 women undergoing letrozole-stimulated IUI at four public fertility clinics in Denmark will be randomly allocated to one of two groups:
Read more
- Vaginal progesterone from the day after insemination (Cyclogest 400 mg twice daily)
- No luteal phase support, reflecting current clinical practice
All participants will undergo a standard letrozole-stimulated IUI treatment, including ultrasound monitoring, ovulation triggering, and insemination. Blood samples will be collected on the day of insemination and 7-9 days after insemination to measure hormone levels.
The results of this trial will provide further insight into the role of progesterone support in letrozole-stimulated IUI cycles.
- Conditions
- Infertility
- Being tested
- Progesterone
- Keywords
- Luteal phase support, Intrauterine insemination, Letrozole, Vaginal progesterone, Randomized clinical trial, Ovulation induction
- Medical subject headings
- Infertility
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ProgesteroneDrug
Also called Cyclogest
Vaginal progesterone (Cyclogest) 400 mg administered twice daily starting the day after insemination. Treatment is continued until gestational age 10 weeks in the event of clinical pregnancy or until clinical pregnancy is ruled out.
| Study group | Role | What they receive |
|---|---|---|
| Intervention | Experimental | Vaginal progesterone luteal phase support. Progesterone is administered as Cyclogest 400 mg twice daily form the day after insemination. Treatment is continued until gestational age 10 weeks in the event of clinical pregnancy, or until pregnancy is ruled out in women who do not achieve a clinical pregnancy. Receives: Drug: Progesterone |
| Comparison | No intervention | No luteal phase support will be administered after insemination, reflecting current standard treatment. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Clinical Pregnancy Rate
Defined as an ultrasonographically visible foetal heartbeat at 7-9 weeks of gestation
Measured: Gestational age 7-9 weeks
Secondary outcomes (7)
Live Birth Rate
Defined as the birth of one or more living infants after a pregnancy of GA ≥ 22 weeks
Measured: At the time of delivery
Biochemical Pregnancy Rate
Defined as a positive serum or urine β-hCG test 14-17 days after intrauterine insemination
Measured: 14-17 days after intrauterine insemination
Early Pregnancy Loss
Defined as intrauterine pregnancy loss before 10 weeks of gestational age
Measured: Up to 10 weeks of gestation
Fetal miscarriage
Defined as pregnancy loss ≥ 10 weeks size with a fetus (≥ 33 mm) on ultrasound
Measured: From 10 weeks of gestation to delivery
Obstetric outcomes
Obstetric complications including hypertensive disorders of pregnancy, gestational diabetes, postpartum hemorrhage and cesarean section
Measured: At time of delivery
Perinatal outcomes
Preterm birth, birth weight, congenital malformations, and perinatal mortality (defined as foetal or neonatal death from GA 22+0 to 7 days after birth).
Measured: At time of delivery
Hormone levels
Serum hormone levels measured on the day of insemination, in the mid-luteal phase and on the day of ovulation trigger (optional), including progesterone, estradiol, LH and FSH.
Measured: Time of insemination and mid-luteal phase (approximately 7-9 days after insemination).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Apr 2026
- Study start28 Aug 2026
- Primary completionJun 2029 (estimated)
- Study completionJan 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for InfertilityStudies 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
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 690 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Kirstine Kirkegaard
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Kirstine Kirkegaard, University of Aarhus
- Investigators
- Kirstine Kirkegaard, Clinical Associate Professor, Principal investigator, University Clinic for Fertility, Horsens Regional Hospital, Central Denmark Region
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07508657
- Sponsor's protocol ID
- 05112025
- Other IDs
- 2025-524327-53-00, 2025
- Acronym
- LIFT
- Status last verified
- Sep 2026
- First submitted
- 27 Mar 2026
- Last updated
- 9 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be made avaliable.
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Luteal Phase Support Following Letrozole Treatment in Women Undergoing Intrauterine Insemination: a Multicenter Randomized Trial
- ClinicalTrials.gov ID
- NCT07508657
- Acronym / sponsor ID
- LIFT / 05112025
- Conditions
- Infertility
- Keywords
- Luteal phase support, Intrauterine insemination, Letrozole, Vaginal progesterone, Randomized clinical trial, Ovulation induction
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 690 participants (estimated)
- Lead sponsor
- Kirstine KirkegaardUniversity, hospital or other
- Study start
- 28 Aug 2026 (actual)
- Primary completion
- Jun 2029 (estimated)
- Study completion
- Jan 2030 (estimated)
- First posted
- 2 Apr 2026 (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.
This trial aims to investigate whether luteal phase support improves the chance of pregnancy in women undergoing intrauterine insemination (IUI) following ovarian stimulation with letrozole.
In this randomized clinical trial, 690 women undergoing letrozole-stimulated IUI at four public fertility clinics in Denmark will be randomly allocated to one of two groups:
- Vaginal progesterone from the day after insemination (Cyclogest 400 mg twice daily)
- No luteal phase support, reflecting current clinical practice
All participants will undergo a standard letrozole-stimulated IUI treatment, including ultrasound monitoring, ovulation triggering, and insemination. Blood samples will be collected on the day of insemination and 7-9 days after insemination to measure hormone levels.
The results of this trial will provide further insight into the role of progesterone support in letrozole-stimulated IUI cycles.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Intervention | Experimental | Drug: ProgesteroneVaginal progesterone luteal phase support. Progesterone is administered as Cyclogest 400 mg twice daily form the day after insemination. Treatment is continued until gestational age 10 weeks in the event of clinical pregnancy, or until pregnancy is ruled out in women who do not achieve a clinical pregnancy. |
| Comparison | No intervention | –No luteal phase support will be administered after insemination, reflecting current standard treatment. |
Who may qualify
- Ages
- 18 to 37 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Age 18-37 years
- Scheduled for IUI with homologous or donor sperm
- Undergoing mild ovarian stimulation with letrozole
- Ability to provide written informed consent
Key exclusion criteria (9 listed)
- Age > 37 years
- Anovulation due to hypogonadotropic hypogonadism
- Known hypersensitivity to progesterone or hard fat listed as an excipient in the Summary of Product Characteristics (SmPC) for Cyclogest.
- Known or suspected progesterone-sensitive malignant tumours
- Porphyria
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 |
|---|---|---|
| ProgesteroneAlso: CyclogestVaginal progesterone (Cyclogest) 400 mg administered twice daily starting the day after insemination. Treatment is continued until gestational age 10 weeks in the event of clinical pregnancy or until clinical pregnancy is ruled out. | Drug | Intervention |
Primary outcome
Clinical Pregnancy Rate
Time frame: Gestational age 7-9 weeks
Defined as an ultrasonographically visible foetal heartbeat at 7-9 weeks of gestation
7 secondary outcomes
Live Birth Rate
Time frame: At the time of delivery
Biochemical Pregnancy Rate
Time frame: 14-17 days after intrauterine insemination
Early Pregnancy Loss
Time frame: Up to 10 weeks of gestation
Fetal miscarriage
Time frame: From 10 weeks of gestation to delivery
Obstetric outcomes
Time frame: At time of delivery
Perinatal outcomes
Time frame: At time of delivery
Hormone levels
Time frame: Time of insemination and mid-luteal phase (approximately 7-9 days after insemination).
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be made avaliable.
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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.
Kirstine Kirkegaard, Clinical Associate Professor principal investigator
University Clinic for Fertility, Horsens Regional Hospital, Central Denmark Region
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Progesterone in people with Infertility, run by Kirstine Kirkegaard at 4 sites in Denmark.
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 4 inclusion and 9 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: looking for participants now, as of the sponsor's last update on 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Kirstine Kirkegaard, Clinical Associate Professor (+4578426562, fertilitet@horsens.rm.dk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Clinical Pregnancy Rate (time frame: Gestational age 7-9 weeks). 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 9 Sep 2026.