Objective: The effect of state/condition of spermatozoa (fresh/motile, fresh/immotile, frozen/motile and frozen/immotile) to fertilization, embryo formation/development, implantation and pregnancy/delivery and abortion rates were studied.
Study design: The data of a total of 167 TESE-ICSI-ET cycles with fresh and cryopreserved, motile and immotile testicular spermatozoa collected with testicular biopsy from patients suffering from non-obstructive azoospermia were analyzed retrospectively. Analysis of variance (ANOVA) was used to distinguish the group effects in fertilization, embryo formation, and implantation ratio. The group effect was evaluated by using non-parametric statistics and the independent grouping variable was also the "semen state/condition". "Semen state/condition" groups were created according to fresh or frozen, and motile or non-motile (immotile) characteristics. For comparing the four groups, Kruskal-Wallis ANOVA and Median-test was applied. The analysis was carried out using Statistica for Windows (StatSoft, Inc., Chicago, USA).
Results: Independently of state/condition of testicular spermatozoa injected into oocytes, no differences were found in fertilization and implantation/pregnancy rates. No difference was obtained in embryo development of oocytes injected with fresh/immotile or frozen/motile spermatozoa. However, difference was found in embryo development of oocytes injected with fresh/motile or frozen/immotile testicular spermatozoa (87% vs. 73%; P<0.04). Comparing embryo development of oocytes injected with fresh vs. frozen spermatozoa difference was also found (83% vs. 74%; P<0.01). No difference was found in the abortion rates between the groups. Differences were observed in the implantation rates, however, these differences could not be verified statistically.
Conclusion: The presented data show that condition of injected testicular spermatozoa has influence to embryo development and even frozen/immotile testicular spermatozoa is able to induce/support fertilization and early embryo development.