Comparing two doses of vaginal progesterone for frozen embryo transfers

A Phase III Randomized Controlled Trial Comparing the Efficacy, Safety and Tolerability of Two Formulations of Vaginal Micronized Progesterone

Phase 3 Interventional Fundacion Dexeus · NCT05899010

This study is testing whether a lower dose of vaginal progesterone can help women achieve successful pregnancies just as well as a higher dose during frozen embryo transfers.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment1020 (estimated)
Ages18 Years to 50 Years
SexFemale
SponsorFundacion Dexeus Academic / other
Locations1 site (Barcelona)
Trial IDNCT05899010 on ClinicalTrials.gov

What this trial studies

This randomized, non-inferiority trial aims to evaluate the ongoing pregnancy rates in women undergoing frozen embryo transfer (FET) cycles with two different doses of vaginal micronized progesterone. Participants will be primed with transdermal estradiol before being randomized to receive either 600 mg or 800 mg of vaginal progesterone during the luteal phase. The study will monitor serum progesterone levels prior to embryo transfer to ensure appropriate luteal phase support. The goal is to determine if the lower dose is as effective as the higher dose in achieving successful pregnancies.

Who should consider this trial

Good fit: Ideal candidates are women aged 18-43 undergoing an autologous IVF cycle or women under 50 following an egg donation cycle, with a BMI between 18 and 30.

Not a fit: Patients with uterine diseases, recurrent pregnancy loss, or contraindications to hormonal treatment may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could optimize progesterone dosing in FET cycles, potentially improving pregnancy outcomes for women undergoing fertility treatments.

How similar studies have performed: Other studies have explored progesterone dosing in fertility treatments, but this specific comparison of doses in the context of frozen embryo transfers is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Endometrial preparation with hormone replacement therapy
* Age 18-43 years following an autologous IVF cycle (with or without preimplantation genetic testing for aneuploidy)
* Age \< 50 years following an egg donation cycle
* BMI \> 18 and \< 30 kg/m2
* blastocyst embryo transfer
* Willing to participate in the study
* Able to come to the Center to comply with the procedures of the study: blood tests, appointments and drug dispensation.

Exlusion Criteria:

* • Uterine diseases (e.g. submucosal fibroids, polyps, previously diagnosed Müllerian abnormalities)
* Hydrosalpinx
* Recurrent pregnancy loss (≥ 3 previous miscarriages)
* Recurrent implantation failure (≥ 3 previously failed embryo transfers of good-quality blastocysts)
* Allergy to study medication
* Pregnancy or lactation
* Contraindication for hormonal treatment
* Personalized initiation of exogenous progesterone according to a previous endometrial receptivity assay test
* Recent history of severe disease requiring regular treatment (clinically significant concurrent medical condition that could compromise subject safety or interfere with the trial assessment).

Where this trial is running

Barcelona

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 Infertility
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.