Intracytoplasmic injection of fresh and cryopreserved testicular spermatozoa in patients with nonobstructive azoospermia--a comparative study.

OBJECTIVE: To compare the outcome of intracytoplasmic sperm injection (ICSI) with fresh and frozen-thawed testicular spermatozoa in patients with nonobstructive azoospermia.

DESIGN: Retrospective analysis of consecutive ICSI cycles.

SETTING: In Vitro Fertilization Unit, Assaf Harofeh Medical Center.

PATIENT(S): Eighteen with nonobstructive azoospermia in whom testicular sperm was found after testicular sperm extraction.

INTERVENTION(S): Testicular sperm retrieval, cryopreservation, and ICSI with fresh or frozen-thawed testicular spermatozoa.

MAIN OUTCOME MEASURE(S): Two-pronuclear fertilization; embryo cleavage rates, mean number of embryos transferred per cycle, and their relative quality, embryo implantation, clinical pregnancy, and ongoing pregnancy rates (PRs) per ET.

RESULT(S): No statistically significant differences were noted in all parameters examined between ICSI cycles with fresh or cryopreserved testicular spermatozoa from the same nine patients and comparing all ICSI cycles performed; with fresh (25 cycles) and thawed (14 cycles) testicular spermatozoa, respectively: two-pronuclear fertilization, 47% versus 44%; embryo cleavage rates, 94% versus 89%; implantation rates, 9% versus 11%; and clinical PR, 26% versus 27%. The delivery or ongoing PR using fresh sperm was better (21% versus 9%), but the difference did not reach statistical significance. The cumulative clinical PRs and ongoing PRs per testicular sperm extraction procedure were 36% and 24%, respectively.

CONCLUSION(S): Testicular sperm cryopreservation using a simple freezing protocol is promising in patients with nonobstructive azoospermia augmenting the overall success achieved after surgical sperm retrieval.