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Study on Progesterone and Estradiol for Infertility in Patients Undergoing Hormone Replacement Therapy with Frozen Embryo Transfer

Registered drugNo placebo
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What is this trial about?

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

This clinical trial is focused on studying infertility and involves the use of two treatments: Estrofem and Cyclogest. Estrofem is a film-coated tablet containing estradiol, a form of estrogen, which is a hormone that plays a key role in the reproductive system. Cyclogest is a pessary, which is a type of medication inserted into the body, containing progesterone, another important hormone for pregnancy. The purpose of this study is to explore the effectiveness of rectally administered progesterone for supporting the luteal phase, which is a part of the menstrual cycle, in hormone replacement therapy frozen embryo transfer (HRT-FET) cycles.

Participants in the study will receive either the rectal form of progesterone or a different form of luteal phase support. The study will monitor the ongoing pregnancy rate at week 12 after the embryo transfer. The trial will also look at other factors such as the levels of progesterone in the blood and urine, any side effects, and the convenience of using the rectal form of Cyclogest. The study aims to determine if the rectal administration of progesterone is as effective as other methods used in HRT-FET cycles.

The trial will continue until the end of 2026, with recruitment starting in November 2023. Participants will be monitored for various outcomes, including the rate of positive pregnancy tests, clinical pregnancies, pregnancy loss, and any complications during pregnancy, such as high blood pressure or preeclampsia. The study will help to understand the best way to support the luteal phase in women undergoing HRT-FET cycles.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, eligibility is confirmed based on criteria such as age (18-46 years), body mass index (BMI) between 18.5 and 34 kg/m², and availability of a day 5 vitrified blastocyst for transfer after thawing.

    Participants must speak and understand Danish.

  2. Step 2

    Medication administration

    The study involves the use of two medications: Estrofem 2 mg Filmtabletten and Cyclogest 400mg.

    Estrofem is taken orally in the form of a film-coated tablet.

    Cyclogest is administered rectally as a pessary.

  3. Step 3

    Treatment phase

    The main objective is to support the luteal phase in hormone replacement therapy frozen embryo transfer (HRT-FET) cycles.

    The study aims to determine the ongoing pregnancy rate at week 12 after using rectally administered progesterone.

  4. Step 4

    Monitoring and evaluation

    Primary evaluation includes the ongoing pregnancy rate at week 12.

    Secondary evaluations involve measuring positive hCG rates, clinical pregnancy, pregnancy loss, live birth rate (LBR), and mean progesterone (P4) levels.

    Urine progesterone levels and side effects related to the rectal administration of Cyclogest are also assessed.

  5. Step 5

    Completion of the study

    The study is estimated to conclude by December 31, 2026.

    Participants' experiences and any complications during pregnancy, such as hypertension and preeclampsia, are documented.

Who can join the trial?

4 criteria

  • You must be a woman aged between 18 and 46 years old.
  • Your BMI (Body Mass Index) should be more than 18.5 and less than 34. BMI is a measure that uses your height and weight to work out if your weight is healthy.
  • You need to have a day 5 vitrified blastocyst available for transfer after thawing. A blastocyst is an embryo that has developed for five days after fertilization, and vitrification is a method of freezing it.
  • You should be able to speak and understand Danish.

Who cannot join the trial?

10 criteria

  • Participants must not have any medical conditions that could interfere with the study.
  • Participants should not be taking any medications that could affect the study results.
  • Participants must not have any allergies to the study medication.
  • Participants should not be pregnant or breastfeeding at the time of the study.
  • Participants must not have participated in another clinical trial recently.
  • Participants should not have any history of drug or alcohol abuse.
  • Participants must not have any serious health conditions that could affect their safety during the study.
  • Participants should not have any mental health conditions that could interfere with their ability to follow study instructions.
  • Participants must not have any known sensitivity to progesterone, which is a hormone involved in the study.
  • Participants should not have any conditions that affect their ability to absorb medications properly.
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Investigated drugs

Micronized Progesterone is used in this study to support the luteal phase in hormone replacement therapy during a frozen embryo transfer cycle. It is administered rectally to help maintain the uterine lining and support early pregnancy. The study aims to determine if this method is as effective as other forms of progesterone administration in achieving a successful pregnancy.

What is already known about the treatment

Micronized Progesterone – This medication is administered rectally and is being studied for its effectiveness in supporting the luteal phase during hormone replacement therapy in frozen embryo transfer cycles. It is currently under investigation in clinical trials to determine its non-inferiority compared to vaginal administration for the same purpose. The main therapeutic indication is to aid in achieving and maintaining pregnancy in individuals undergoing fertility treatments. At the molecular level, progesterone works by preparing the uterine lining for implantation and maintaining a supportive environment for early pregnancy. It is classified as a progestin, a type of hormone that mimics the effects of natural progesterone in the body.

Investigated diseases

Infertility – Infertility is a condition where an individual or couple is unable to conceive a child after a year of regular, unprotected sexual intercourse. It can affect both men and women and may result from various factors, including hormonal imbalances, structural problems, or lifestyle factors. In women, infertility may be due to issues such as ovulation disorders, blocked fallopian tubes, or uterine abnormalities. In men, it can be caused by low sperm count, poor sperm motility, or blockages that prevent sperm delivery. The condition can be temporary or permanent, depending on the underlying cause. Infertility can lead to emotional stress and may require medical intervention to achieve pregnancy.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-504616-15-02Estimated enrolment618 patientsSponsorRegion Midtjylland

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