RANDOMIZED TRIAL OF PARTIAL ZONA DISSECTION FOR MALE-INFERTILITY

Objectives: To compare IVF rates using partial zona dissection versus zona intact insemination in couples with male infertility. To analyze pregnancy rates relative to sperm characteristics, fertilization rates , and treatment. Design: Randomized prospective comparison of fertiliz ation in sibling oocytes. Transfer of the three best quality embryos f rom one or both treatments. Setting: Department of Gynaecology and Rep roductive Medicine, University Hospital, London, Ontario, Canada. Part icipants: Thirty-two couples undergoing IVF with a principal diagnosis of male infertility. Intervention: Treatment with partial zona dissec tion. Main Outcome Measures: Fertilization and pregnancy. Results: Fer tilization rates were 26% and 9% after partial zona dissection and IVF , respectively. Polyspermy was <1% in each treatment. There were five singleton pregnancies in 29 completed cycles, three in cycles with fer tilization only by partial zona dissection and two in cycles with both partial zona dissection and IVF fertilization. There were no pregnanc ies after fertilization by IVF only. Stepwise logistic regression anal ysis indicated that pregnancy was related to partial zona dissection, initial sperm concentration, and total acrosin activity. Conclusion: P artial zona dissection was associated with minimal polyspermic fertili zation and higher normal fertilization rates than sibling oocytes trea ted by modified IVF. Pregnancy occurred only after transfer of embryos from partial zona dissection or combined partial zona dissection and IVF.