Impact of Microfluidic Sperm Sorting on Embryonic Euploidy in Infertile Patients with Sperm DNA Damage: A Retrospective Study.

Background: Sperm DNA fragmentation is an important factor that affects male fertility. This study intends to evaluate the impact of sperm DNA damage [single-strand breaks (SSB) and double-strand breaks (DSB)] on fertilisation and embryonic euploidy after intracytoplasmic sperm injection (ICSI). Of the different sperm selection techniques, the novel microfluidic sperm sorting (MSS) ZyMōt™ ICSI device reduces both SSB and DSB in semen samples. The second objective is to study the impact of this MSS device on fertilisation and embryonic euploidy.

Materials and methods: This retrospective study included data from 167 ICSI treatments. The alkaline and neutral Comet assays were used to analyse SSB and DSB, respectively. Analysis of fertilisation and embryo euploidy rates was performed in four groups of patients with normal/altered SSB or DSB values. Density gradient centrifugation (DGC) and the ZyMōt™ ICSI MSS device were used for semen preparation.

Results: Fertilisation rates in 167 ICSI cycles were higher when using sperm from patients with normal SSB values (70.84%) and patients with abnormal SSB whose samples were processed using the MSS device (69.71%) compared to patients with abnormal SSB values using DGC (58.49%). Preimplantation genetic testing for aneuploidies (PGTA) revealed a higher embryo euploidy rate in patients with normal DSB values (60.00%) and patients with abnormal DSB whose samples were processed using the MSS device (44.59%) compared to patients with abnormal DSB values using DGC (36.84%). When female age was considered, there were fewer euploid embryos in women ≥35 years of age compared to younger women, independently of SSB and DSB. The number of euploid embryos increased when the MSS device was used.

Conclusion: High SSB and DSB values in semen samples decreased fertilisation rates and embryonic euploidy, respectively. The ZyMōt™ ICSI device for semen preparation increased both rates, especially in couples that included women <35 years old.