NCT06741748

Direct Warming Frozen Embryo Transfer Outcomes in Assisted Reproductive Technology

A Pragmatic, Multi-centre, Double-blinded, Two-arm Randomized Controlled Trial on a Direct Warming Frozen Embryo Transfer in Assisted Reproductive Technologies Treatment Outcome

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 578 (estimated)
• Sponsor: Chinese University of Hong Kong · Academic / Other
• Sex: Female
• Age: 18 Years – 45 Years
• Healthy volunteers: Not accepted

Summary

The goal of this clinical trial is to evaluate whether the direct warming method for frozen embryo transfers (FET) can improve live birth and pregnancy outcomes in women aged 18-45 undergoing IVF treatments. The main questions it aims to answer are: * Does the direct warming method achieve a similar or higher clinical success rate for FET compared to the conventional multi-step method? * Is the direct warming method more cost-effective than the conventional method? Researchers will compare the direct warming method to the conventional multi-step method to see if the former leads to better pregnancy outcomes and reduced procedural time. Participants will: * Undergo either the one-step or conventional embryo thawing procedure. * Complete standard clinical follow-ups for pregnancy, including ultrasound scans and pregnancy tests.

Detailed description

This clinical trial explores a novel direct warming method for frozen embryo transfer (FET), aimed at improving both clinical and operational outcomes in assisted reproductive technologies (ART). The method was designed to simplify and accelerate the embryo thawing process, reducing the time needed for thawing while eliminating the use of cryoprotectants commonly required in conventional thawing methods. This innovation has the potential to offer a more efficient and cost-effective alternative to standard FET procedures. The primary focus of this trial is to compare the clinical effectiveness of the direct warming method against the conventional multi-step thawing process. In particular, the study seeks to determine whether the new method yields comparable or superior outcomes in terms of clinical pregnancy rate (CPR), ongoing pregnancy rate (OPR), and live birth rate (LBR), while also assessing its overall cost-effectiveness. Study Design and Technical Details This study employs a randomized controlled design, with participants being allocated into either the intervention group (direct warming method) or the control group (conventional multi-step thawing). The direct warming method streamlines the thawing process to just 3 minutes, in contrast to the conventional method, which requires multiple stages and takes approximately 20 minutes. By using only an embryo culture medium without cryoprotectants, the direct warming method reduces both complexity and potential risks associated with handling and cryoprotectant toxicity. Key Objectives * Primary Objective: To evaluate the clinical efficacy of the direct warming method in achieving comparable or higher success rates for FET as compared to conventional multi-step thawing. * Secondary Objective: To assess the cost-effectiveness of the direct warming method by comparing the consumable and time costs across different centers. Expected Impact and Innovation The direct warming method challenges the traditional multi-step thawing approach, offering a faster and simpler alternative without compromising clinical outcomes. By minimizing the need for cryoprotectants and reducing the complexity of the thawing process, the new method is expected to enhance the overall efficiency of FET procedures while maintaining or improving pregnancy success rates. Additionally, the cost and time savings associated with the direct warming method may make it a viable option for IVF clinics worldwide, driving standardization and consistency across clinical settings.

Conditions

• Frozen Embryo Transfer (FET)
• Assisted Reproductive Techniques
• In Vitro Fertilization (IVF)
• Cryopreservation of Embryos
• Pregnancy Outcome After in Vitro Fertilization (IVF)

Interventions

Type	Name	Description
OTHER	Direct Warming Method	This intervention involves thawing vitrified blastocysts using a simplified, one-step direct warming method. The blastocyst is placed in a pre-warmed embryo culture medium for approximately one minute, then transferred directly into the embryo culture medium within a time-lapse system until ready for uterine transfer. The total thawing process takes approximately three minutes, reducing the duration and complexity of the procedure compared to conventional methods.
OTHER	Conventional Multi-step Thawing Method	This intervention involves thawing vitrified blastocysts using a standard, multi-step process. The procedure includes sequential exposure of the blastocyst to different thawing solutions containing varying concentrations of cryoprotectants, followed by its transfer into an embryo culture medium in a time-lapse system. The overall process takes approximately 10-30 minutes.

Timeline

• Start date: 2025-09-01
• Primary completion: 2026-10-31
• Completion: 2027-10-31
• First posted: 2024-12-19
• Last updated: 2025-03-11

Locations

3 sites across 2 countries: Hong Kong, United Kingdom