Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not recruiting

Study on Vaginal Progesterone for Improving Live Birth Rates in Women with Infertility Undergoing Frozen/Thawed IVF Natural Cycles

Fast replyRegistered drug
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

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, a condition where individuals have difficulty getting pregnant. The study is investigating the use of vaginal progesterone as a treatment to support the luteal phase, which is a part of the menstrual cycle that occurs after ovulation. The trial aims to determine if using vaginal progesterone can improve the chances of a live birth for women undergoing a specific type of fertility treatment called frozen/thawed in-vitro fertilization natural cycles (FET-NC). Two forms of progesterone are being used in this study: Cyclogest 400 mg vagitorium and Lutinus 100 mg vaginaltabletter.

The purpose of the study is to see if providing luteal phase support with vaginal progesterone is better than not providing any support, in terms of achieving a live birth. If it is found to be beneficial, the study will also compare whether a 7-week treatment is more effective than a 3-week treatment. Participants in the study will receive either the progesterone treatment or a placebo, and their progress will be monitored over time to assess various outcomes related to pregnancy and birth.

Throughout the study, researchers will track several outcomes, including live birth rates, pregnancy progression, and any complications that may arise during pregnancy. The study will also look at the cost-effectiveness of the treatment and measure progesterone levels in blood samples. The trial is expected to continue until early 2026, with the goal of providing valuable insights into the effectiveness of vaginal progesterone in supporting successful pregnancies for those experiencing infertility.

The research process

The trial runs in 6 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, body mass index (BMI), regular menstrual cycles, and language proficiency.

    Informed consent is required to participate in the study.

  2. Step 2

    Treatment initiation

    The study involves the use of vaginal progesterone as luteal support during frozen/thawed in-vitro fertilization natural cycles.

    Participants are randomly assigned to receive either no luteal phase support or vaginal progesterone treatment.

  3. Step 3

    Medication administration

    If assigned to the progesterone group, participants will use either Cyclogest 400 mg pessary or Lutinus 100 mg vaginal tablet.

    The medication is administered through vaginal use.

  4. Step 4

    Treatment duration

    The study aims to determine if 7 weeks of progesterone treatment is more effective than 3 weeks.

    Participants will follow the assigned treatment duration as part of the study protocol.

  5. Step 5

    Monitoring and follow-up

    Throughout the study, various outcomes such as live birth, pregnancy status, and progesterone levels in blood samples will be monitored.

    Participants will undergo regular check-ups to assess the progress and any potential side effects.

  6. Step 6

    Study completion

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

    Final assessments will be conducted to evaluate the effectiveness of the treatment in improving live birth rates.

Who can join the trial?

6 criteria

  • Planned for a FET-NC with a blastocyst. FET-NC stands for Frozen Embryo Transfer in a Natural Cycle, which is a process where a frozen embryo is placed in the uterus during a natural menstrual cycle.
  • Age between 18 and 42 years old.
  • BMI between 18.5 and 34.9. BMI stands for Body Mass Index, which is a measure of body fat based on height and weight.
  • Regular menstrual cycles lasting between 24 and 35 days.
  • Have given informed consent, meaning you agree to participate after understanding the study details.
  • Ability to understand written and spoken Swedish, English, or Arabic.

Who cannot join the trial?

3 criteria

  • Individuals who are not experiencing infertility cannot participate. Infertility means having difficulty getting pregnant.
  • Participants must be women, as men are not included in this study.
  • Participants must not belong to a vulnerable population. A vulnerable population includes groups of people who might need special protection or care.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

Vaginal Progesterone is used in this trial as a form of luteal phase support. It is administered to women undergoing frozen/thawed in-vitro fertilization natural cycles (FET-NC) to see if it improves the chances of a live birth. The study aims to determine if using vaginal progesterone is better than not using any luteal phase support. Additionally, the trial seeks to find out if a longer duration of progesterone treatment (7 weeks) is more effective than a shorter duration (3 weeks).

What is already known about the treatment

Progesterone – This medication is administered vaginally and is used as a form of luteal phase support in women undergoing frozen embryo transfer in natural cycles. It is currently being studied in clinical trials to determine its effectiveness in improving live birth rates compared to no luteal support. Progesterone is primarily indicated for infertility treatment, particularly in assisted reproductive technologies. At the molecular level, progesterone works by preparing the uterine lining for implantation and maintaining pregnancy. It is classified as a progestin, which is a type of hormone therapy.

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 issues, or lifestyle factors. In women, infertility may be due to problems with ovulation, fallopian tubes, or the uterus. In men, it often involves issues with sperm production or function. 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 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-512844-40-00Protocol codeProFETEstimated enrolment1 800 patientsSponsorVaestra Goetalandsregionen

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

Tell us about your condition – we search every trial in Europe and connect you with the right site.

ClinicalTrials.eu

Every clinical trial in Europe, in plain language.

Explore the full ecosystem of clinical research in Europe.

Search trials

Legal notice · Published by CTIN POLAND sp. z o.o., ul. rtm. Witolda Pileckiego 67/109, 02-781 Warsaw, Poland · KRS 0001111334 · REGON 528919042 · NIP 9512598637

© 2026 Clinical Trials EU – European Clinical Trials Information Network

GDPR compliance, ISO 9001 and ISO 27001 certified (LL-C Certification)

On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).