Intracytoplasmic Sperm Injection Clinical Outcomes: A Non-Inferiority Comparison of The Novel Felix™ Electrophoretic System and Conventional Density Gradient Centrifugation for Sperm Selection, A Prospective Clinical Trial.

Abstract

Objective: In intracytoplasmic sperm injection (ICSI), sperm selection has traditionally relied on motility and morphology, often overlooking DNA integrity. This study evaluates the Felix™ Electrophoretic System, which isolates sperm based on membrane surface electric charge, by assessing its effectiveness in selecting motile sperm with intact DNA and comparing ICSI clinical outcomes between the Felix™ system and density gradient centrifugation (DGC) in sibling oocytes.

Materials and methods: In this prospective clinical trial study, semen samples from 25 infertile couples were processed using both DGC and the Felix™ sperm preparation system. For ICSI, oocytes were fertilized with sperm prepared by each method. Embryo development was monitored using time-lapse imaging, and embryo quality was assessed on day 5 post-ICSI. The highest-quality embryo from each group was selected for transfer.

Results: Fertilization rates and blastocyst quality were comparable between the two groups. Although the Felix ™ group exhibited a higher proportion of high-quality blastocysts than the DGC group, this difference was not statistically significant (P=0.220). The number of embryo transfers per couple varied depending on the availability of transferable embryos. In total, 16 embryo transfers were performed in the Felix™ group, resulting in a 37% clinical pregnancy rate, whereas 11 transfers were performed in the DGC group, resulting in a 36% clinical pregnancy rate.

Conclusion: This pilot study demonstrated that the Felix™ system provides assisted reproductive technology (ART) outcomes comparable to those of DGC, while requiring less semen and time and avoiding centrifugal stress. However, larger studies and additional functional and long-term evaluations are needed to confirm its efficacy, safety, and impact on offspring health (registration number: IRCT20110804007223N11).