Effect of limited proteolysis with alpha-chymotrypsin on semen with an abnormal sperm penetration assay and possible application for in vitro fertilization or intrauterine insemination.

This study was designed to assess the impact of limited proteolysis with alpha-chymotrypsin on the sperm penetration assay (SPA) of infertile patients and to identify a group whose results would normalize with this pretreatment. Further, the application of this treatment to semen of these patients during in vitro fertilization (IVF) and intrauterine insemination (IUI) was reported. Three groups were identified. In one, SPA was abnormal and improved to normal with pretreatment; in the second, SPA was abnormal and did not normalize; and in the third, SPA was normal and improved significantly (included in this group are three known fertile controls). Chymotrypsin pretreatment and repeat SPA are advocated for patients with abnormal SPA. If normalization occurs, pretreatment of semen for IVF or IUI is a therapy to be considered.