Patient guide
Sperm Freezing — When and Why
A guide to sperm cryopreservation — when to consider it, how the process works, and what to expect from frozen-thawed sperm in IVF.
Who Should Consider Sperm Freezing?
- Before cancer treatment (chemotherapy, radiation, testicular surgery)
- Before vasectomy (backup banking)
- Low sperm count that may worsen — preserve now
- Difficulty producing a sample on demand (IVF retrieval day pressure)
- Men with occupational exposure to reproductive toxins
- Long absences from home during planned IVF cycle
How Sperm Freezing Works
- Produce a semen sample by masturbation (2–5 days of abstinence recommended)
- Sample analysed immediately in the andrology laboratory
- Sperm washed and mixed with cryoprotectant medium
- Loaded into straws and slowly cooled to -196°C in liquid nitrogen
- Stored in liquid nitrogen tanks — can be preserved for decades
What to Expect After Thawing
Post-thaw survival varies by sample quality. Typically 50–70% of motile sperm survive freeze-thaw. Frozen sperm is excellent for ICSI (where a single sperm is selected), even with modest post-thaw parameters.
When Surgical Sperm Freezing is Needed
For men with azoospermia or very severe OAT, sperm can be retrieved surgically (TESA, PESA, or mTESE) and frozen for future ICSI cycles. This avoids the need to coordinate surgery with your partner's egg retrieval day.