Effectiveness of Live Motile Sperm Sorting Device on IVF Outcomes in Advanced Paternal Age

Male infertility contributes to approximately 50% of all infertility cases. One of the essential steps in assisted reproductive technology (ART) is sperm preparation, which aims to select motile, morphologically normal spermatozoa with minimal DNA damage. However, conventional sperm preparation techniques involving centrifugation may increase oxidative stress and sperm DNA fragmentation. The live motile sperm sorting device LensHooke® CA0 has been proposed as an alternative to traditional density gradient centrifugation (DGC), aiming to reduce sperm damage and potentially improve IVF outcomes.

LensHooke® CA0 offers several advantages: it avoids centrifugation and the mechanical stress associated with it; optimally reduces the DNA fragmentation index (DFI); minimizes the risk of premature acrosome reaction (AR); is suitable for both normozoospermic and non-normozoospermic semen samples; simplifies workflow (only three pipetting steps required: loading, medium addition, and recovery); and ensures a high degree of standardization, reducing inter-technician variability.

Moreover, paternal age is an important factor influencing sperm quality and fertility potential. Studies have demonstrated that men over 40 years of age exhibit higher sperm DNA fragmentation rates, increased morphological and motility abnormalities, and are associated with a higher incidence of embryonic chromosomal abnormalities and reduced live birth rates. Therefore, this population particularly requires optimized sperm selection methods to improve IVF/ICSI outcomes.

This study aims to evaluate the clinical value of this device through two primary objectives:

1. To compare sperm quality post-processing and the DNA fragmentation index between the CA0 method and the conventional DGC method in advanced paternal age group.
2. To compare the rates of blastocyst formation, euploid embryos, and clinical pregnancy between the two sperm preparation techniques in advanced paternal age group.

• LensHooke® CA0 sperm sorting device (Device): Sperm will be processed using the CA0 device by loading 1.0 mL of semen into the lower chamber and adding 0.9 mL of pre-equilibrated sperm washing medium into the upper chamber. The device is incubated at 37 °C for a minimum of 30 minutes, followed by aspirating 0.5 mL of recovered sperm suspension for ICSI.
• Density Gradient Centrifugation (Device): Sperm will be prepared by layering 1 mL of 45% medium and 1 mL of 90% medium with 1 mL of semen sample. This is followed by a first centrifugation at 1500 rpm for 15 minutes, a wash step using 2 mL G-IVF plus medium, and a second centrifugation at 1200 rpm for 10 minutes to retain 0.5 mL of the sperm suspension.

Primary outcomes

• Clinical Pregnancy Rate after single embryo transfer [4 to 6 weeks after embryo transfer]: Confirmed by the presence of an intrauterine gestational sac on ultrasound.

Secondary outcomes

• Post-processing sperm DNA fragmentation index (DFI, %) [Immediately after sperm preparation on the day of oocyte retrieval]: Evaluated using the LensHooke® R11 Plus assay
• Blastocyst rate and good-quality blastocysts rate [Day 5 to Day 6 after ICSI]: Evaluated according to Gardner's criteria and classified following Munné et al. (2019)
• Euploidy rate. [Within 2 weeks after blastocyst biopsy]: Assessed via preimplantation genetic testing for aneuploidy (PGT-A) using next-generation sequencing (NGS).

Sex: All, ages: 40 Years to any

Inclusion Criteria:

* Male partners aged ≥ 40 years
* Semen analysis: volume ≥ 1.4 mL, sperm concentration ≥ 6 million/mL, progressive motility (PR) ≥ 20% after 3-5 days of abstinence.
* Female partners with ≥ 5 mature (MII) oocytes retrieved.
* Couples undergoing ICSI with PGT-A and elective single embryo transfer (eSET).
* Willingness to participate and sign informed consent.

Exclusion Criteria:

* Azoospermia, surgical sperm retrieval, or use of cryopreserved sperm.
* Female uterine or ovarian conditions severely affecting IVF outcomes.
* Use of donor sperm or donor oocytes