Comparing endometrial preparation methods for frozen embryo transfer

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

Phase 4 Interventional Rahem Fertility Center · NCT06181305

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
Enrollment210 (estimated)
Ages18 Years to 37 Years
SexFemale
SponsorRahem Fertility Center Academic / other
Locations1 site (Zagazig)
Trial IDNCT06181305 on ClinicalTrials.gov

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.

Who should consider this trial

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

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.

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

Eligibility criteria

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 this trial is running

Zagazig

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions IVF
Last reviewed 2026-06-13 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.