A comparison of ICSI outcomes with fresh and cryopreserved epididymal spermatozoa from the same couples

The published experience with frozen-thawed epididymal spermatozoa and intracytoplasmic sperm injection (ICSI) suggests that fertilization and pregnancy success rates are comparable to those achieved with freshly retrieved spermatozoa. However, no study has exactly compared clinical outcomes between the two IVF/ICSI cycles in the same couples. To formally address this issue, we assessed ICSI outcomes in couples each of whom had had two IVF/ICSI cycles: one using fresh and the second using frozen-thawed epididymal spermatozoa obtained from a single aspiration procedure. From a pool of 101 consecutive patients undergoing IVF/ICSI with epididymal spermatozoa, 19 couples initially used fresh epididymal spermatozoa and subsequently underwent a second IVF/ICSI procedure with frozen-thawed spermatozoa from the same aspiration. Normal (2PN) oocyte fertilization rates, embryo quality and pregnancy rates were compared between the two IVF/ICSI cycles for each couple. In the fresh epididymal sperm group, 58.4% of the injected oocytes fertilized normally compared with 62.0% of the injected oocytes in the frozen-thawed epididymal sperm group, revealing no statistically significant difference. Graded embryo quality also did not differ significantly between the paired IVF/ICSI cycles. The clinical pregnancy rates were 31.6% (6/19) and 36.8% (7/19) in the first and second cycles respectively. All but one pregnancy were singletons. In summary, this study provides strong evidence to support the notion that motile, cryopreserved and thawed epididymal spermatozoa are equal to freshly retrieved spermatozoa for ICSI in couples with obstructive azoospermia.