Microfluidic sorting of sperm for assisted reproduction - An evaluation of ZyMōt multi sperm separation device

Abstract: Infertility is a worldwide problem and the main reason for the use of assisted reproductive technol- ogy (ART). In-vitro fertilization (IVF) is one ART treatment normally used, where the fertilization of oocytes occurs in vitro. The quality of the spermatozoa has a great impact on the outcome of IVF, highlighting the importance of obtaining spermatozoa with the highest fertilization potential. For this, different sperm preparation techniques are used where the density-gradient centrifugation (DGC) method is generally preferred. However, it is discussed whether the centrifugation step in this method affects the spermatozoa negatively, and new methods using microfluidics have recently appeared on the market, one being the ZyMōt Multi Sperm Separation Device. In this study, 25 semen samples were split and prepared with either DGC or ZyMōt. The aim was then to compare the prepared samples regarding 4 main parameters. (1) The proportion of motile spermatozoa, (2) the degree of motility, (3) the yield, and (4) the amount of sperm DNA fragmentation (SDF) was assessed by microscopic examination. An evaluation of the level of oxidative stress (OS) in the native semen samples was also performed. Significant differences were observed for SDF (p < 0,0001) and the proportion of motile spermatozoa (p < 0,0001) where samples prepared with ZyMōt displayed better results. Moderate evidence was observed for a difference regarding the yield between the methods (p = 0,04647), where DGC generated a higher total amount of sperma- tozoa. No difference in the degree of motility was observed. No correlation between the level of OS in the origin semen sample and SDF in the prepared samples was observed. The results of this study indicate that ZyMōt generates good-quality samples containing a high number of motile sper- matozoa with almost no DNA fragmentation. ZyMōt also proved to be a simpler method to per- form, improving laboratory efficiency.