Objective: To assess the efficacy of fresh vs. frozen testicular sperm on fertilization and pregnancy using intracytoplasmic sperm injection.
Design: Retrospective study.
Setting: Hospital-based infertility research laboratory.
Patient(s): One hundred sixty patients with obstructive azoospermia undergoing testicular sperm extraction (TESE).
Intervention(s): Sections of seminiferous tubule were cryopreserved after TESE. Sperm motility and fertilizing ability were determined after thawing seminiferous tubule sections.
Main outcome measures: Sperm motility and optimal fertilization and pregnancy rate.
Result(s): Intracytoplasmic sperm injection was performed using fresh testicular sperm (fresh-sperm group; 84 cases) and thawed seminiferous tubules (thawed-sperm group; 177 cases). The overall fertilization rate was 65.4%, and the pregnancy rate was 34.0%. In the fresh-sperm group, the fertilization rate was 70.9%, and the pregnancy rate was 38.8%. In the thawed-sperm group, the fertilization rate was 62.7%, and the pregnancy rate was 21.7%. Fertilization rates were higher using fresh motile sperm vs. nonmotile sperm (77.0% vs. 29.3%). Pregnancy rates were higher using fresh motile sperm vs. nonmotile sperm (44.3% vs. 20.0%). The fertilization and pregnancy rates of motile vs. nonmotile sperm extracted from the thawed seminiferous tubule were 70.0% vs. 50.9% and 33.9% vs. 27.3%, respectively. Motile spermatozoa could be obtained several hours after thawing in most of the cases.
Conclusion(s): Optimal fertilization and pregnancy rates were achieved using fresh vs. frozen sperm obtained using TESE when motile sperm were identified. Motile spermatozoa provided superior results to nonmotile sperm and are necessary for optimal fertilization and pregnancy outcomes.