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Published on: May 27, 2022
Impact of Sperm Retrieval Yield and Freezing on ICSI Outcomes in Non-Obstructive Azoospermia: A Retrospective Study
Li Lei1,2,3,4, Ming Li1,2,3,4, Qingqing Tao5
1State Key Laboratory of Female Fertility Promotion, Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China.
Background:
Microdissection testicular sperm extraction is the preferred method for sperm retrieval in men with non-obstructive azoospermia. However, the effects of sperm retrieval quantity and freezing on intracytoplasmic sperm injection outcomes remain incompletely understood.
Objectives:
To evaluate the impact of sperm quantity and freezing status on fertilization and cumulative live birth rate following intracytoplasmic sperm injection using microdissection testicular sperm extraction spermatozoa in non-obstructive azoospermia patients.
Materials And Methods:
We retrospectively analyzed 1394 microdissection testicular sperm extraction-intracytoplasmic sperm injection cycles performed between 2017 and 2022 at a single tertiary center. Sperm retrieval yield was stratified into three groups: sufficient sperm count (> 10 spermatozoa/100 fields), low sperm count (6-10/100), and extremely low sperm count (1-5/100). Fertilization rate (two pronuclei) and cumulative live birth rate were compared across sperm retrieval yield and freezing subgroups. Multivariable regression and interaction models assessed the independent and combined effects of sperm quantity and freezing status.
Results:
Fertilization and cumulative live birth rate declined significantly with reduced sperm counts (two pronuclei: 53.6%→32.2%; cumulative live birth rate: 49.8%→21.8%; p < 0.001). Frozen spermatozoa yielded comparable outcomes to fresh spermatozoa overall, but in the extremely low sperm count group, frozen spermatozoa were associated with a significantly lower cumulative live birth rate than fresh spermatozoa (12.3% vs. 29.3%; p = 0.015). Interaction analysis confirmed this adverse effect (OR = 0.39; 95% CI 0.16-0.95; p = 0.038). No significant freezing effect was observed in the other groups.
Conclusion:
Sperm retrieval quantity is an important predictor of intracytoplasmic sperm injection success in men with non-obstructive azoospermia. Freezing generally does not affect outcomes, but may significantly reduce live birth rates when sperm availability is extremely limited. Prioritizing the use of fresh spermatozoa in such cases may improve clinical outcomes.
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