Selection of spermatozoa is one the most important factors that influence embryonic development and clinical outcome in intracytoplasmic sperm injection (ICSI). Intracytoplasmic morphologically selected (IMSI) a technique selects only according to their features under high magnification. However, there another selection uses hyaluronic acid (HA) select physiologically mature (HA-ICSI). The purp...

Prior to ICSI the cumulus-oophorous-complex of the oocyte is commonly remove with impure animal-derived hyaluronidase of low strength. The lower strength of the enzyme, the high concentration of impurities and the necessity of extensive time-dependent mechanical denudation damages of the oocytes, increases the risk of lysing the oocytes and the transfer of animal-derived pathogens. All this can...