Impact of Endometrial Compaction on Reproductive Outcomes After Cryotransfer of Euploid Embryos in a Natural Cycle

Recruiting

• Conditions: Infertility Due to Nonimplantation
• Interventions: Other: Observational non intervention study

• Registration Number: NCT05960370
• Lead Sponsor: Instituto Bernabeu

Brief Summary

Multicenter prospective observational cohort study, comparing ongoing pregnancy rates in natural cycles for euploid embryo transfer in patients who present endometrial compaction at the time of the transfer versus those who have a stable or greater endometrial thickness with respect to the estrogenic phase.

Detailed Description

Multicenter prospective observational cohort study. Based on our sample size calculation, the study group will consist of 206 women (exposed or "compaction" group: 103 women with a decrease of ≥ 5% in endometrial thickness between the estrogenic phase and the day of embryo transfer; non-exposed "non-compaction" group: 103 women with similar or greater endometrial thickness between these time points). The main objective of this study is to compare the ongoing pregnancy rates in natural cycles for euploid embryo transfer in patients who present endometrial compaction at the time of transfer versus those who with a stable or greater endometrial thickness with respect to the estrogenic phase. The estimated duration of the study is 24-30 months. Inclusion criteria are: 18 to 50 years of age, with primary or secondary infertility, subjected to endometrial preparation in a modified natural cycle for transfer of a genetically euploid blastocyst, from their own oocyte or oocyte donation, with a normal uterine cavity. Exclusion criteria are: uterine or endometrial disease (e.g., multiple myomatosis, severe adenomyosis, Asherman syndrome, refractory endometrium), conditions that prevent correct ultrasound assessment (tilted uterus), or a history of recurrent implantation failure or repeated miscarriages.

Study Timeline

• Study Start: 2022-06-15
• Study First Submitted: 2023-07-17
• Study First Submitted QC: 2023-07-24
• Study First Posted: 2023-07-25
• Status Verified: 2024-10
• Last Update Submitted: 2024-10-02
• Last Update Posted: 2024-10-03
• Primary Completion: 2025-06-15
• Study Completion: 2025-06-15

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Female
• Target Recruitment: 206

Inclusion Criteria

• Aged 18 to 50 years
• Primary or secondary infertility
• Normal uterine cavity
• Endometrial preparation in a modified natural cycle for single embryo transfer
• Embryo in blastocyst state from own oocyte or oocyte donation cycles, who had normal results on preimplantation genetic testing for aneuploidy (PGT-A) via trophectoderm biopsy.

Exclusion Criteria

• Uterine or endometrial disease (multiple myomatosis [>3 fibroids of > 3 cm], adenomyosis, Asherman syndrome)
• Difficulties in correctly measuring endometrial thickness due to a retroverted or tilted uterus
• History of recurrent implantation failure (3 or more transferred blastocysts of good quality, from their own oocyte [<35 years] or oocyte donation); recurrent early Pregnancy Loss (the loss of two or more pregnancies before 10 weeks of gestational age.
• Suboptimal endometrial response (endometrium < 6 mm on the day of ovulation triggering).

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
exposed or "compaction" group	Observational non intervention study	103 women with a decrease of ≥ 5% in endometrial thickness between the estrogenic phase (ovulation induction day) and the day of embryo transfer (7 days after ovulation induction).
non-exposed "non-compaction" group	Observational non intervention study	103 women with similar or greater endometrial thickness between the estrogenic phase (ovulation induction day) and the day of embryo transfer (7 days after ovulation induction).

Primary Outcome Measures

Name	Time	Method
Ongoing pregnancy rate	8-10 weeks gestational age.	Presence of an intrauterine pregnancy with positive embryo heartbeat as seen by sonography at 8-10 weeks gestational age.

Secondary Outcome Measures

Name	Time	Method
Ectopic pregnancy	5-8 weeks gestational age.	ultrasonic or surgical visualization of a pregnancy outside of the endometrial cavity.
Biochemical pregnancy loss	9-10 days after the embryo transfer.	Spontaneous pregnancy demise based on decreasing serum b-hCG levels, without an ultrasound evaluation.
Early pregnancy loss	5-10 weeks gestational age.	spontaneous pregnancy demise before 10 weeks of gestational age (before 8th developmental week).
Clinical pregnancy	5-6 weeks gestational age.	A pregnancy diagnosed by ultrasonographic visualization of one or more gestational sacs or definitive clinical signs of pregnancy.

Trial Locations

Locations (1)

Instituto Bernabeu; 🇪🇸 Madrid, Spain