Outcomes in couples undergoing ICSI: comparison between fresh and frozen-thawed surgically retrieved spermatozoa

We retrospectively evaluated the impact of cryopreservation on spermatozoa obtained from patients with azoospermia and used for intracytoplasmic sperm injection (ICSI). Frozen-thawed epididymal spermatozoa (FTEPS) was used in 34 couples, whereas frozen-thawed testicular spermatozoa (FTTS) was used in 50 couples for ICSI during assisted conception, and these results were compared with results using fresh spermatozoa for ICSI in the same individuals. The fertilization rate (FR) was significantly lower for FTTS (65.8%) but not for FTEPS (73.1%) compared with the FR using fresh spermatozoa (72.3% and 73.2% respectively). In contrast, neither the implantation nor the pregnancy rate was altered when FTEPS or FTTS was used. In conclusion, our results indicate that surgically retrieved spermatozoa can be efficiently used for ICSI after freezing and thawing without compromising the outcome.