Clinical implications of intracytoplasmic sperm injection using cryopreserved testicular spermatozoa from men with azoospermia

OBJECTIVE: To investigate whether sperm obtained by testicular sperm extraction (TESE) and cryopreserved well before intracytoplasmic sperm injection (ICSI) can serve as an effective sperm source. STUDY DESIGN: The role of cryopreserved testicular spermatozoa was evaluated in a retrospective analysis of consecutive ICSI cycles using fresh or cryopreserved sperm; they were followed by prospective, planned treatment using cryopreserved sperm with a modified ICSI procedure. Sixteen men (22 cycles) with obstructive or nonobstructive azoospermia were included in the retrospective analysis. Another 25 men (29 cycles) were in the planned treatment group. Following these series, the pregnancy outcomes were compared between ICSI cycles with fresh or cryopreserved testicular sperm. RESULTS: In the retrospective phase, 14 ICSI cycles were performed using fresh sperm, with 8 using cryopreserved sperm. There were no statistically significant differences between the two groups in any outcome measure. Planned treatment with cryopreserved sperm resulted in a fertilization rate of 84% and an embryo transfer rate of 89%. Thirteen couples (44%) achieved pregnancy (five ongoing, six delivered). These rates were similar to those in the retrospective phase of the study. All couples in the planned cryopreservation group had multiple aliquots (6.5 ± 2.1) of sperm remaining after the first cycle. CONCLUSION: Cryopreserved sperm obtained by TESE can be used as an effective sperm source in ICSI cycles. Planned cryopreservation allows multiple aliquots to be stored for use in subsequent cycles and thus avoids need for repeat biopsies.