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A study of progesterone after letrozole treatment for women with infertility undergoing intrauterine insemination

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on Infertility, a condition where a person has difficulty conceiving a child. The research involves women who have undergone intrauterine insemination, a procedure where sperm is placed directly inside the uterus to help with fertilization, following treatment with letrozole, a medication used to stimulate the ovaries. The main goal is to determine if adding progesterone, a hormone that helps prepare the lining of the uterus for pregnancy, can improve the chances of a successful pregnancy.

Participants in the study may receive either Cyclogest, which is a form of progesterone delivered as a pessary through vaginal use, or a placebo. The luteal phase refers to the period in the menstrual cycle after ovulation occurs and before the next period begins, a time when hormone levels are critical for supporting a developing pregnancy. By comparing these two groups, the study aims to see how supplementation affects outcomes such as pregnancy rates and various health factors during pregnancy and birth.

The research process

The trial runs in 2 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Medication administration

    After the treatment with letrozole (a medication used to stimulate the ovaries), progesterone must be administered.

    The medication is cyclogest 400 mg, which is a vaginal pessary (a small, solid medication inserted into the vagina).

    A total dose of 800 mg is used to provide luteal phase support, which helps prepare the lining of the uterus for a potential pregnancy.

  2. Step 2

    Monitoring and outcomes

    Hormone levels may be measured on the day of insemination (the procedure where sperm is placed inside the uterus), during the mid-luteal phase (the middle part of the time between ovulation and the next period), and at the time of the ovulation trigger (the medication used to induce the release of an egg).

    The progress is monitored to assess the clinical pregnancy rate, which is the rate of confirmed pregnancies.

    Subsequent monitoring includes the live birth rate, biochemical pregnancy rate (a very early sign of pregnancy detected by hormone levels), and any instances of early pregnancy loss or miscarriage.

    Outcomes related to the pregnancy, such as birth weight, preterm birth (birth before the full term), and gestational diabetes (high blood sugar during pregnancy), are also recorded.

Who can join the trial?

6 criteria

  • You must be between 18 and 37 years old.
  • You are planning to undergo intrauterine insemination, which is a procedure where sperm is placed directly inside the uterus to help with pregnancy.
  • The sperm used can be from a partner or a donor, which is a person who provides sperm for reproductive purposes.
  • You must be receiving mild ovarian stimulation, a process using medication to encourage the ovaries to produce eggs.
  • The medication used for this stimulation must be letrozole.
  • You must be able to provide written informed consent, which means you understand the study and sign a document agreeing to participate.

Who cannot join the trial?

9 criteria

  • Being older than 37 years of age.
  • Not ovulating (not releasing an egg) because of hypogonadotropic hypogonadism, which is a condition where the brain does not send enough signals to the ovaries to trigger ovulation.
  • Having a known hypersensitivity, or an allergic reaction, to progesterone or to hard fat, which are ingredients used in the study medication.
  • Having or suspected having malignant tumours (cancer) that are sensitive to progesterone.
  • Having porphyria, which is a group of rare genetic disorders that affect the production of certain chemicals in the body.
  • A known history of missed abortion (when a pregnancy ends but the body does not immediately show signs) or ectopic pregnancy (when a fertilized egg grows outside the main area of the womb).
  • Having an active thromboembolism, which is a blood clot in an artery or vein, thrombophlebitis, which is inflammation of a vein caused by a blood clot, or having a history of these conditions.
  • Having severe hepatic dysfunction, which means the liver is not working properly, or having liver disease.
  • Being unable to speak or understand Danish well enough to understand all the written and spoken information about the study.
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Investigated drugs

Progesterone is a hormone used as a supplement to support the lining of the uterus, which helps in the possibility of a successful pregnancy.

What is already known about the treatment

Cyclogest - This medication is a hormone pill called a pessary that is inserted into the vagina to be absorbed through the vaginal wall. It is a well-established treatment used to support pregnancy and manage hormonal imbalances, particularly in women struggling to conceive. It works by mimicking the natural hormone progesterone, which helps prepare and maintain the lining of the uterus so a fertilized egg can attach and grow. This substance belongs to a group of medicines known as progestogens.

Investigated diseases

Infertility - This condition occurs when a person or couple is unable to achieve pregnancy after regular, unprotected sexual intercourse. It can involve difficulties with ovulation, the health of the reproductive organs, or issues with sperm quality. The process may progress as a persistent inability to conceive over several months. It often stems from hormonal imbalances or physical obstructions within the reproductive system.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2025-524327-53-00Protocol codeLIFTEstimated enrolment690 patientsSponsorRegion Midtjylland

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