Clinical trial No longer in our active list Phase 4 Interventional Ages 18 to 37 Women only

Comparing endometrial preparation methods for frozen embryo transfer

Official title: Hormonal Replacement Therapy Plus Letrozole Incorporation Versus Letrozole Mild Ovarian Stimulation in Endometrial Preparation for Frozen Embryo Transfer: A Randomised Controlled Trial

Run by Rahem Fertility Center · NCT06181305 · Data updated 2026-05-14

This study is no longer in our active list. It may have stopped recruiting or finished. The details below are as of 2026-05-14 and are kept for reference. Check ClinicalTrials.gov for its current status, or see similar studies below.

This study is testing whether using mild ovarian stimulation with letrozole or hormonal replacement therapy with letrozole works better for women aged 18 to 37 in preparing their bodies for frozen embryo transfers to improve pregnancy rates.

Quick facts

PhasePhase 4
Study typeInterventional
Ages18 Years to 37 Years
SexWomen only
Enrollment210 (estimated)
SponsorRahem Fertility Center
Academic / other
Locations1 site (Zagazig)
Trial IDNCT06181305 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates are women aged 18 to 37 with regular or irregular menstrual cycles undergoing frozen embryo transfer.

Probably not a fit

Patients who do not have at least one good-quality blastocyst for transfer or those who refuse to participate will not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This study aims to compare two different methods of preparing the endometrium for frozen embryo transfer (FET) cycles: mild ovarian stimulation using letrozole versus hormonal replacement therapy (HRT) combined with letrozole. The goal is to determine which method yields better reproductive outcomes, particularly focusing on pregnancy rates and potential complications. Participants will include women aged 18 to 37 with good-quality blastocysts available for transfer. The study will assess the effectiveness of these protocols in synchronizing the embryo stage with the endometrium to optimize pregnancy success.

Why it matters

Potential benefit: If successful, this study could improve pregnancy rates and reduce complications associated with frozen embryo transfers.

How similar studies have gone: Previous studies have shown promising results with similar approaches, particularly the incorporation of letrozole in endometrial preparation.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Women aged between 18 and 37 years with either regular cycles or oligomenorrhoea or amenorrhoea.
* Women undergoing FET cycles.
* Participants should have at least one good-quality blastocyst available for vitrification and also for transfer after warming.
* Participants having optimal endometrium before starting luteal phase support

Exclusion Criteria:

* Women who will refuse to participate in in the study.
* Women who will not reach the optimal endometrium.
* Participants that don't have at least one good-quality blastocyst for transfer after warming.
* PGT embryos will be excluded.

Where it's running

  • Rahem fertility center
    Zagazig, Egypt
    Recruiting

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
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Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.