Andrology
January 21, 2026 · via Europe PMC
Impact of Sperm Retrieval Yield and Freezing on ICSI Outcomes in Non-Obstructive Azoospermia: A Retrospective Study of 1394 Micro-TESE Cycles.
Lei L, Li M, Tao Q, +7 more, Li R.
AI summary — for doctors, generated from the abstract only
In a large retrospective study of men with non-obstructive azoospermia, lower sperm retrieval counts during testicular sperm extraction were associated with lower fertilization and live birth rates after ICSI, and freezing sperm further reduced live birth rates specifically when very few sperm were available.
What was studied
A retrospective analysis of 1,394 microdissection testicular sperm extraction-ICSI cycles performed between 2017 and 2022 at a single tertiary center in men with non-obstructive azoospermia, comparing fertilization rate and cumulative live birth rate across three sperm retrieval yield groups (sufficient, low, and extremely low sperm counts) and by whether sperm were fresh or frozen.
Key findings
- Fertilization rate (two pronuclei) declined significantly as sperm counts decreased, from 53.6% in the sufficient-count group to 32.2% in the extremely-low-count group
- Cumulative live birth rate also declined significantly with lower sperm counts, from 49.8% to 21.8% (exact p-value not fully available in the retrieved abstract text)
- Freezing sperm generally did not affect outcomes, but significantly reduced live birth rates specifically in the extremely-low sperm count group
Clinical relevance
The findings suggest that when very few sperm are retrieved in men with non-obstructive azoospermia, using fresh rather than frozen sperm for ICSI may improve the chance of a successful outcome, which could inform decisions about sperm freezing versus fresh-cycle planning in this challenging patient group.
Who should care
Limitations
This is a retrospective, single-center study, so while the large sample size (1,394 cycles) strengthens the findings, unmeasured factors specific to the treating center's practices could limit how the results generalize elsewhere.
Lower sperm counts retrieved from testicular extraction were linked to lower ICSI success, and freezing those scarce sperm further reduced live birth chances, suggesting fresh sperm may be preferable when counts are extremely low.
This is an AI-generated summary of the published abstract, not a clinical recommendation. It may not reflect the full text or subsequent updates — verify against the original source before acting on it.
Abstract
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.
DOI
10.1111/andr.70180
PMID
41566914
Research metadata (titles, abstracts, authors, publication dates) is sourced from Europe PMC, which aggregates content from PubMed/MEDLINE, PubMed Central, and other providers under the U.S. National Library of Medicine (NLM/NCBI). NLM does not claim copyright on abstracts; the original journal publishers or authors may hold rights to the full articles. AI-generated summaries are derived only from the abstract, never the full text, and are always labeled as AI-generated.
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