Outcomes of Microdissection Testicular Sperm Extraction/Intracytoplasmic Sperm Injection in Cases of Nonobstructive Azoospermia: A Retrospective Study

Abstract

The outcomes and safety of intracytoplasmic sperm injection (ICSI) using testicular sperm have been controversial. We evaluated ICSI results, pregnancy outcomes, and neonatal health conditions using testicular sperm from patients with obstructive (OA) or nonobstructive (NOA) azoospermia. We further compared the ICSI outcomes after use of fresh versus cryopreserved testicular sperm from men with NOA. We included 314 men with NOA who underwent microdissection testicular sperm extraction (mTESE) and 303 with OA who underwent testicular sperm aspiration; both groups underwent ICSI. Therefore, 101 and 329 ICSI cycles were performed for mTESE and aspirated sperms, respectively. Furthermore, fresh and thawed embryos from both groups were transplanted to evaluate fertilization and pregnancy rates (NOA, 15 fresh and 123 thawed; OA, 59 fresh and 393 thawed). Finally, of the 101 ICSI cycles performed for NOA patients, 56 fresh-sperm cycles and 45 thawed-sperm cycles were performed to evaluate ICSI outcomes. Fertilization rates and two-pronuclear (2PN) fertilization rates were significantly lower in the NOA group than in the OA group. However, the 2PN cleavage rate, the high-quality embryo rate, the blastocyst formation rate, and the available blastocyst rate showed no significant intergroup differences. In addition, the pregnancy outcomes and neonatal health conditions were statistically similar. Finally, compared with thawed sperm, the fresh-sperm group had a higher 2PN fertilization rate and a higher high-quality embryo rate. However, blastocyst formation and available blastocyst rates were similar between the two groups. Patients with NOA achieved the same favorable results in embryo development, clinical pregnancy, and live birth capability as did OA patients. Neonatal conditions were not affected by type of azoospermia (NOA versus OA). For patients with NOA, fresh testicular sperm is superior to frozen-thawed testicular sperm in embryo development as evaluated at the cleavage stage, but we find no superiority evaluating at the stage of blastocyst formation.