What is Sperm Freezing?
Sperm freezing, or sperm cryopreservation, is the process of collecting, freezing and storing sperm at very low temperatures (-196°C in liquid nitrogen) for future use. Unlike egg freezing, sperm cryopreservation has been used successfully for decades and is technically simpler. Frozen sperm can be stored for many years — sometimes decades — with minimal loss of quality. When needed, the sperm is thawed and used in fertility treatments such as intrauterine insemination (IUI) or in vitro fertilisation (IVF), often combined with intracytoplasmic sperm injection (ICSI).
Who Should Consider Sperm Freezing?
Men diagnosed with cancer who are about to start chemotherapy or radiotherapy, both of which can permanently impair sperm production
Patients undergoing surgery that may affect fertility (e.g., testicular surgery, prostate surgery)
Men with degenerative or progressive conditions affecting sperm quality
Those undergoing gender-affirming hormone therapy who want to preserve the option of biological children
Men in high-risk occupations (military, certain industrial roles)
Couples preparing for IVF where the male partner may have difficulty producing a sample on the day
Men with very low or declining sperm counts who want to bank what they have
The Sperm Freezing Process
Initial consultation: Discussion of medical history, blood tests for infectious diseases (HIV, hepatitis), and consent forms.
Sample collection: Usually produced by masturbation in a private room at the clinic. Surgical sperm retrieval is available for men who cannot ejaculate or have azoospermia.
Sample analysis: The lab assesses sperm count, motility (movement) and morphology (shape) to determine quality and how to process it.
Cryoprotectant addition: A protective solution is mixed with the sample to prevent ice crystal damage during freezing.
Freezing and storage: The sample is divided into multiple vials (so you do not have to thaw everything at once) and stored in liquid nitrogen.
Multiple samples: Typically 2-3 samples are collected on different days to maximise the amount stored and account for natural variation.
Success and Survival Rates
Sperm survives freezing and thawing remarkably well. Around 50-80% of sperm typically survive the freeze-thaw process, though this varies by individual. Frozen sperm has been used to achieve pregnancies after more than 20 years of storage. Pregnancy rates with frozen sperm are comparable to fresh sperm when used in IVF/ICSI. For IUI, success rates may be slightly lower than with fresh samples but remain a viable option, particularly if a good number of motile sperm are recovered after thawing.
Costs, Timing and Storage Duration
Sperm freezing is significantly less expensive than egg freezing. Initial freezing costs typically range from £200-£500 per sample, with annual storage fees of £150-£300. Many fertility clinics, hospitals and the NHS (for medical indications such as cancer) offer the service. The process is fast — samples can be collected, processed and frozen within a few hours, making it suitable even for men needing to start cancer treatment urgently. In the UK, sperm can now be stored for up to 55 years with periodic consent renewals.
When to Act
Immediately after a cancer diagnosis and before any treatment begins — even one cycle of chemotherapy can affect sperm DNA
Before any surgery that might affect fertility
Before starting medications known to affect sperm production
If your sperm count is declining and you may want children later
Before gender-affirming hormone therapy