AuthorisedTherapeutic use (Phase IV)Interventional

Luteal phase support following letrozole treatment in women undergoing intrauterine insemination: a multicenter randomized trial

This research is investigating whether giving a medication called Cyclogest (a progesterone suppository) to women after they've had fertility treatment makes a difference. The treatment involves a medicine called letrozole to help with ovulation, followed by intrauterine insemination (IUI). Doctors want to see if using Cyclogest helps more women become pregnant and have a successful birth. They will compare how many women get pregnant and have healthy babies in the group receiving Cyclogest versus those who don't. This study is an important step in finding the best ways to support women going through fertility treatment.

At a glance

Status

Authorised

Phase

Therapeutic use (Phase IV)

Sponsor

Region Midtjylland

Enrolment target

690

Start

09 Mar 2026

Infertility

What is this study about?

This medical study is designed to see if a particular treatment helps women who are trying to get pregnant with the help of fertility doctors. When women are having difficulty getting pregnant, they might try treatments like taking a medicine called letrozole, which helps release eggs, followed by a procedure called intrauterine insemination (IUI). IUI involves placing sperm directly into the womb.

The main question this study wants to answer is whether giving a medication called Cyclogest makes it more likely for women to become pregnant and carry their baby to term after letrozole and IUI. Cyclogest is a hormone (progesterone) that is given as a pessary (a small tablet placed into the vagina). Progesterone helps prepare the womb for pregnancy and supports the early stages of pregnancy.

Researchers will be looking closely at how many women become pregnant and how many have a healthy baby. They will also be tracking other important health information, such as the health of the baby at birth, any potential problems during pregnancy like early miscarriage or high blood pressure, and the overall health of the mother.

Key takeaways

This study evaluates Cyclogest (progesterone) after fertility treatment.
It's for women experiencing infertility undergoing letrozole and IUI.
Researchers will check if Cyclogest increases pregnancy and live birth rates.
Participation involves your regular fertility care plus study-specific monitoring.
You might receive Cyclogest or not, based on a random assignment.

Who may be eligible?

This study is open to adult women who are aged 18 or older. It specifically focuses on women who are experiencing infertility, meaning they are having trouble getting pregnant.

To be considered for this study, you would likely be undergoing fertility treatment that involves taking the medication letrozole, followed by a procedure called intrauterine insemination (IUI). Your fertility doctor will be able to tell you if this study might be suitable for you based on your personal medical situation.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you an adult woman, aged 18 or older?
Are you currently receiving fertility treatment for infertility?
Is your treatment plan expected to include letrozole and intrauterine insemination (IUI)?
Are you able to attend regular clinic appointments for your fertility care and study follow-up?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you would continue with your planned fertility treatment involving letrozole and intrauterine insemination (IUI). The main difference would be that you would then be randomly assigned to either receive the Cyclogest medication (a vaginal pessary) or not, after your IUI procedure.

Throughout the study, you would have regular visits with your fertility clinic, just as you normally would for your fertility treatment. Doctors would monitor your progress, such as checking for pregnancy. They would also collect information about your pregnancy and the health of your baby if you become pregnant, up until after birth. These check-ups might also involve some blood tests at certain times to measure hormone levels, but this would be optional for some tests. The total time you would be involved in the study would depend on how long it takes to become pregnant and to follow up on the birth of your baby.

Potential risks and benefits

Taking part in this study may offer the potential benefit of improving your chances of getting pregnant and having a successful live birth, although this is what the study aims to find out. As with any medication, Cyclogest can have side effects, which your doctor will discuss with you. These are generally mild and can include things like vaginal irritation. There is also the potential that the medication may not help. You have the right to withdraw from the study at any time without giving a reason, and this will not affect your ongoing medical care.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

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Unverified
Denmark

Common questions

What is the main goal of this study?

The main goal is to see if using a medication called Cyclogest after fertility treatment (letrozole and IUI) helps women get pregnant more often.

What is Cyclogest?

Cyclogest is a medication that delivers a hormone called progesterone, usually given as a small tablet (pessary) inserted into the vagina, which can help support early pregnancy.

What is IUI?

IUI stands for Intrauterine Insemination. It's a fertility treatment where sperm is placed directly into the womb.

Will I definitely get the active drug if I join?

No, you will be randomly assigned to either receive Cyclogest or not, so researchers can compare the results fairly.

How long will I be involved in the study?

Your involvement would cover your fertility treatment and follow-up during pregnancy and after birth, if you become pregnant.