Two-dimensional planar swimming selects for high DNA integrity sperm.

Selection of high-quality sperm is critical to the success of assisted reproductive technologies. Clinical screening for top sperm has long focused on sperm swimming ability when following boundaries or when fully free of constraints. In this work, we demonstrate a sperm selection approach with parallel 2 μm tall confined selection channels that prohibit rotation of the sperm head and require planar swimming. We demonstrate that a planar swimming subpopulation of sperm capable of entering and navigating these channels has DNA integrity superior to the freely-swimming motile or raw sperm populations over a wide range of semen sample qualities. The DNA integrity of the selected sperm was significantly higher than that of the corresponding raw samples for donor samples and clinical patient samples, respectively. In side-by-side testing, this method outperforms current clinical selection methods, density gradient centrifugation and swim-up, as well as sperm selected via general motility. Planar swimming represents a viable sperm selection mechanism with the potential to improve outcomes for couples and offspring.