Optimal Timing of Euploid Day 6 Blastocyst Transfer in Frozen HRT Cycles, Day 6 or Day 7 of Progesterone Administration.

Last updated: June 22, 2026
Sponsor: ART Fertility Clinics LLC
Overall Status: Suspended

Phase

1

Condition

Infertility

Treatment

Transvaginal ultrasound

Progesterone 100 Mg Vaginal Insert

Serum LH, E2, P4

Clinical Study ID

NCT05980091
2306-ABU-013-CC
  • Ages 18-43
  • Female
  • Accepts Healthy Volunteers

Study Summary

The goal of this study is to compare the difference in clinical pregnancy, miscarriage and livebirth rate between day 6 euploid blastocyst transfer on the 6th and the 7th day of progesterone exposure in Hormonal Replacement Therapy (HRT) FET cycles. This prospective & randomized study will only include euploid day 6 blastocysts. This will be the first prospective study of euploid day 6 blastocysts thereby excluding aneuploidy as a cause of miscarriage and implantation failure. The point of randomization will occur on the day of progesterone commencement.

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Women aged 18 years to 43 years.

  • Having at least 1 euploid cryopreserved day 6 blastocyst of at least Grade BBquality.

  • Endometrial trilaminar appearance on the day of progesterone start

Exclusion

Exclusion Criteria:

  • Uterine abnormality

  • Hydrosalpinx

  • Asherman syndrome

  • Any known contraindications or allergy to oral estradiol or progesterone.

  • Intention to treat : exclusion factors :

  1. Spontaneous ovulation HRT cycle

  2. Discontinuation of HRT medication

Study Design

Total Participants: 316
Treatment Group(s): 6
Primary Treatment: Transvaginal ultrasound
Phase: 1
Study Start date:
September 22, 2023
Estimated Completion Date:
December 30, 2026

Study Description

Traditionally the duration of progesterone exposure before embryo transfer has been considered equal for day 5 and day 6 embryos but this may not be the case and warrants further study. The optimal preparation of the endometrium in frozen embryo transfer (FET) cycles is yet to be determined. Synchronization between the embryonic stage and the endometrial window of implantation (WOI) is crucial and progesterone plays a critical role in the WOI (1). Data on the optimal route of administration, the dose and duration of progesterone supplementation before blastocyst transfer are inconsistent (2,3). In view of the current lack of evidence, this study will be of importance.

Connect with a study center

  • ART Fertility Clinics LLC

    Abu Dhabi, Abu Dhabi Emirate 60202
    United Arab Emirates

    Site Not Available

  • ART Fertility Clinics Dubai

    Dubai,
    United Arab Emirates

    Site Not Available

Map preview placeholder

Not the study for you?

Let us help you find the best match. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.