What is the success rate of sperm freezing and subsequent pregnancy in individuals with varying sperm quality and fertility treatment protocols?

Sperm Freezing Success Rates

Sperm cryopreservation achieves a 28% pregnancy rate and 20% live birth rate per patient when subsequently used in assisted reproductive technology, based on the largest meta-analysis of over 32,000 men. 1

Overall Success Rates from Sperm Banking

• The 2025 ASCO guideline meta-analysis of 69 studies involving 23,178 patients who cryopreserved sperm reported pregnancy rates of 28%, miscarriage rates of 13%, and delivery rates of 20% per patient. 1
• Only 9% of cryopreserved sperm samples are eventually used in assisted reproductive technology (ART), while 23% are disposed of unused. 1
• Subgroup analyses demonstrate improving outcomes over time, with recent studies showing higher pregnancy and delivery rates compared to older studies. 1

Success Rates by Sperm Quality

Normal to Mildly Reduced Parameters

• Men with adequate sperm concentration and motility achieve pregnancy rates up to 57% using intracytoplasmic sperm injection (ICSI) with frozen-thawed sperm. 1
• A cohort of 272 cancer patients using cryopreserved sperm achieved a live birth rate of 62.1% with ICSI, significantly higher than other ART methods. 1

Severe Oligospermia

• ICSI methodology yields significantly higher pregnancy rates (37.4%) compared to intrauterine insemination (11.5%) when using frozen sperm from men with poor parameters. 2
• Even severely compromised samples can achieve fertilization through ICSI, as only a single viable sperm is required per oocyte. 3

Azoospermia with Surgical Retrieval

• Testicular sperm extraction before gonadotoxic treatment achieves positive sperm retrieval in 42.9%-57.7% of patients, depending on malignancy type. 1
• When testicular sperm is successfully retrieved and frozen, ICSI results in pregnancy rates comparable to ejaculated sperm, with one study reporting two pregnancies from three successful retrievals. 1
• Post-chemotherapy surgical sperm retrieval in men with persistent azoospermia achieves success rates of 37%-44% per patient, with live birth rates of 40%-59% per couple. 1

Impact of Cryopreservation on Sperm Quality

• Sperm concentration and progressive motility decrease significantly after cryopreservation in both cancer patients and healthy donors (P < 0.0001 for all comparisons). 1
• DNA fragmentation of spermatozoa is not significantly affected by cryopreservation (P = 0.829), preserving genetic integrity despite reduced motility. 1, 4
• The frozen-thaw survival rate decreases from 85.72% to 73.98% after 15 years of cryopreservation, though clinical pregnancy rates remain stable. 5

Success Rates by Treatment Protocol

Intrauterine Insemination (IUI)

• Clinical pregnancy rates with frozen donor sperm range from 22.32% to 23.09% across different storage durations (0.5-15 years). 5
• Live birth rates remain stable at 80-82% among women who achieve clinical pregnancy using IUI with frozen sperm. 5

In Vitro Fertilization (IVF)

• Clinical pregnancy rates with frozen sperm in IVF range from 53.48% to 64.94%, with optimal results in samples stored 0.5-10 years. 5
• Live birth rates among pregnant women range from 73.91% to 81.63%, with slight decline after 10 years of storage. 5

Intracytoplasmic Sperm Injection (ICSI)

• ICSI represents the optimal treatment for frozen-thawed sperm with compromised parameters, achieving pregnancy rates of 37.4% even in cancer patients with poor baseline quality. 2
• ICSI requires only a single viable sperm per oocyte, making it effective even when post-thaw recovery is limited. 3

Critical Factors Affecting Success

Pre-Freeze Sperm Quality

• Cancer patients demonstrate significantly lower sperm quality before treatment compared to controls (P = 0.01), which further decreases after treatment (P = 0.001). 1
• Testicular cancer patients show the poorest baseline sperm quality among malignancy types. 2

Collection Recommendations

• Clinicians recommend collecting at least three ejaculates if total motile count (TMC) is ≤25 million, aliquoting each collection to obtain TMC >5 million per sample. 1
• Multiple samples provide backup specimens and maximize total stored sperm, improving future treatment options. 6

Long-Term Storage Viability

• Successful pregnancies and live births have been documented from sperm stored for 21 and 28 years, demonstrating indefinite viability under proper conditions. 7
• Clinical pregnancy rates remain stable (22-23%) across storage durations of 0.5-15 years when using IUI. 5
• Storage beyond 5 years negatively influences frozen-thawed sperm quality parameters, though clinical outcomes remain acceptable. 5

Common Pitfalls to Avoid

• Never initiate exogenous testosterone therapy if fertility preservation is desired, as it completely suppresses spermatogenesis through negative feedback, potentially causing azoospermia requiring months to years for recovery. 6
• Avoid delaying cryopreservation in cancer patients, as 10% fail to cryopreserve sperm if collection is attempted after treatment initiation. 1
• Do not assume single sperm analysis is sufficient—natural variability requires repeat testing to establish baseline parameters. 6
• Recognize that even with elevated FSH and testicular atrophy, up to 50% of men with non-obstructive azoospermia have retrievable sperm via microsurgical extraction. 8