Comparison of the outcome of intracytoplasmic sperm injection using fresh and frozen-thawed epididymal spermatozoa obtained by percutaneous epididymal sperm aspiration

The study was conducted to compare the outcome of intracytoplasmic sperm injection (ICSI) between fresh and frozen-thawed epididymal spermatozoa retrieved by percutaneous epididymal sperm aspiration (PESA) from obstructive azoospermic men. Overall, 53 PESA procedures were performed in 42 obstructive azoospermic men, followed by ICSI procedures with either fresh (n = 40) or frozen-thawed (n = 13) epididymal spermatozoa. Comparing all ICSI cycles with fresh and frozen-thawed epididymal spermatozoa, the fertilization rates (77.4 vs 86.8%) and the cleavage rate (91.3 vs 95.1%) were not statistically different. A total of 64 embryo transfers were performed: 48 embryo transfers after the use of fresh epididymal spermatozoa and 16 embryo transfers after the use of frozen-thawed spermatozoa. The overall pregnancy rate per embryo transfer was also similar between both groups (40.8 vs 40%). The implantation rate per embryo (18.2 vs 12.7%), clinical pregnancy per embryo transfer (36.7 vs 33.3%) and delivery/ongoing pregnancy rate (36.7 vs 33.3%) were not statistically different. In conclusion, there were no significant differences of the outcome of intracytoplasmic sperm injection using fresh and frozen-thawed epididymal spermatozoa obtained by PESA.