Comparing letrozole and artificial cycles for preparing the uterus in women with irregular periods

Letrozole-stimulated Cycle Strategy Versus Artificial Cycle Strategy for Endometrial Preparation in Women With Irregular Menstrual Cycles: A Randomized Controlled Trial

Not applicable Interventional Mỹ Đức Hospital · NCT06372119

This study is testing if using letrozole to prepare the uterus can help women with irregular periods have more successful pregnancies after freezing and transferring embryos compared to using an artificial hormone cycle.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment790 (estimated)
Ages18 Years to 42 Years
SexFemale
SponsorMỹ Đức Hospital Academic / other
Locations2 sites (Ho Chi Minh City, Ho Chi Minh City and 1 other locations)
Trial IDNCT06372119 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the effectiveness of a letrozole-stimulated cycle strategy versus an artificial cycle strategy for endometrial preparation in women experiencing irregular menstrual cycles. Participants will be randomly assigned to receive either letrozole to stimulate follicular development or an artificial cycle regimen using estradiol and progesterone. The primary goal is to determine if the letrozole approach leads to a higher live birth rate after frozen embryo transfer compared to the artificial cycle method. The study addresses a significant challenge in assisted reproduction technology by exploring a more natural preparation method for the endometrium.

Who should consider this trial

Good fit: Ideal candidates are women aged 18 to 42 with irregular menstrual cycles who require endometrial preparation for embryo transfer.

Not a fit: Patients with certain endometrial or uterine abnormalities, or those with a history of recurrent pregnancy loss or implantation failure, may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could improve live birth rates for women with irregular menstrual cycles undergoing frozen embryo transfer.

How similar studies have performed: Previous studies have shown promise in using letrozole for endometrial preparation, suggesting that this approach may be effective, though it is still being explored.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Aged between 18 - 42.
* Irregular menstrual cycle (\< 21 days or \> 35 days or \< 8 cycles/years).
* Indicated for endometrial preparation.
* Transfer of only one blastocyst.
* Not participating in any other trials.

Exclusion Criteria:

* Allergy to letrozole or Ovitrelle or oral estradiol valerate or micronized progesterone
* Having embryos from either oocyte donation or PGT (pre-implantation genetics testings) cycles.
* Ovarian cysts that are unrelated to the oocyte pick-up.
* Confirmed diagnosis with recurrent pregnancy loss (RPL) according to ESHRE guideline 2023, recurrent implantation failure (RIF) according to ESHRE 2023 good practice recommendations.
* Endometrial abnormalities include endometrial hyperplasia, intrauterine adhesions, endometrial polyp, and chronic endometritis.
* Uterine abnormalities include leiomyomas L0, L1, or L2 (according to FIGO 2011); adenomyosis (according to MUSA 2022); congenital uterine abnormalities, include didelphus, arcuate, unicornuate, bicornuate, septate (according to ASRM 2021).
* Untreated hydrosalpinx.

Where this trial is running

Ho Chi Minh City, Ho Chi Minh City and 1 other locations

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 Embryo TransferIrregular MenstruationLetrozoleHormone Replacement TherapyBlastocyst Transfer
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.