A Phase 4 interventional study of Progesterone in Infertility, sponsored by Kirstine Kirkegaard. Recruiting at 4 sites in Denmark. Open to female participants aged 18 Years to 37 Years. Per ClinicalTrials.gov, last updated 2026-09-09.
Sponsored by Kirstine Kirkegaard · Phase 4, Interventional, and Treatment
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:
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.
2,085 studies on the registry are indexed under Infertility; 357 are open to participants now.
This study's planned enrollment of 690 is above the median of 135 across 1,412 interventional studies indexed under Infertility.
Browse Infertility studies →This is the only study on the registry with Kirstine Kirkegaard as lead sponsor.
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Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
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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.
Drug: Progesterone
No luteal phase support will be administered after insemination, reflecting current standard treatment.
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.
Also known as: Cyclogest
Clinical Pregnancy Rate
Defined as an ultrasonographically visible foetal heartbeat at 7-9 weeks of gestation
Time frame: Gestational age 7-9 weeks
Live Birth Rate
Defined as the birth of one or more living infants after a pregnancy of GA ≥ 22 weeks
Time frame: At the time of delivery
Biochemical Pregnancy Rate
Defined as a positive serum or urine β-hCG test 14-17 days after intrauterine insemination
Time frame: 14-17 days after intrauterine insemination
Early Pregnancy Loss
Defined as intrauterine pregnancy loss before 10 weeks of gestational age
Time frame: Up to 10 weeks of gestation
Fetal miscarriage
Defined as pregnancy loss ≥ 10 weeks size with a fetus (≥ 33 mm) on ultrasound
Time frame: From 10 weeks of gestation to delivery
Obstetric outcomes
Obstetric complications including hypertensive disorders of pregnancy, gestational diabetes, postpartum hemorrhage and cesarean section
Time frame: 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).
Time frame: 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.
Time frame: Time of insemination and mid-luteal phase (approximately 7-9 days after insemination).
Plan to share: No — Individual participant data will not be made avaliable.
No publications or documents are linked to this record.
Started Aug 2026 (actual). Primary completion is estimated for Jun 2029, 34 months after the start.
Of 73 non-industry phase 4 interventional studies under Infertility, half reached primary completion within 34 months of starting (the median), counting those still running; a quarter within 19 and three quarters within 82. This study's planned 34 months is close to that.
Counting every sponsor, half of 80 studies reached it within 33 months; a quarter within 19 and three quarters within 82.
How these figures are worked out, and which studies are left out of them.
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Studies of the drug tested here: Progesterone