INTRACYTOPLASMIC SPERM INJECTION FOR TREATMENT OF INFERTILITY DUE TO ACROSOMAL ENZYME DEFICIENCY

Objective: To determine whether absence of fertilization in IVF associ ated with an acrosomal enzyme defect (hyaluronidase deficiency) result s from a simple mechanical block to sperm penetration or from a more s erious sperm abnormality. Design: Nonrandomized, prospective study. Se tting: Toronto Center for Advanced Reproductive Technology, a tertiary referral center for infertility associated with The University of Tor onto. Patients: One hundred twenty-two couples about to undergo intrac ytoplasmic sperm injection (ICSI) were selected. Thirty-six of the stu died couples had failed to fertilize in prior IVF cycles. Intervention s: Hyaluronidase activity was measured in the semen samples provided f or ICSI using a zymogenic assay. Intracytoplasmic sperm injection was performed in all couples using standard techniques. Results: Forty-eig ht of 122 semen samples had poor or absent semen hyaluronidase activit y. All 48 samples resulted in successful fertilization with ICSI in th e present study. The average fertilization rate per oocyte was 59.43% in couples in whom the male partner had low semen hyaluronidase activi ty and 55.85% in whom the male had normal hyaluronidase activity. The ET rate per cycle was 100% and 95% and pregnancy rates per cycle were 26% and 25% in cycles with poor and normal semen hyaluronidase activit y, respectively. Unlike routine IVF, no statistical correlation was fo und between semen hyaluronidase activity and the fertilization rate in ICSI. Conclusion: Our results indicate that semen hyaluronidase defic iency is associated with a simple mechanical block to fertilization. I n addition, the measurement of semen hyaluronidase activity can provid e a reliable means for selecting couples who would benefit from ICSI.