In some circumstances semen freezing might be recommended to couples. In these cases the semen sample is frozen in a specific medium (cryoprotectant) which protects spermatozoa against damage, during the whole freezing process. The frozen sample can be preserved for many years and used for fertility treatment in the future. However, it is important to notice that freezing reduces sperm quality; therefore, fresh samples are preferred on the day required. The legal limit for storage is five years, but it may be extended in certain occasions.
Sperm cryopreservation is indicated for the following reasons:
- For patients with low sperm numbers or are producing sperm that show evidence of deterioration over time.
- For men who find it difficult to ejaculate on demand, this might result in their inability to produce a sample on the day of egg retrieval. Freezing prior to treatment reduces the stress associated with producing a sample.
- For men who require routine surgical sperm retrieval.
- Prior to chemo/radio therapy. Both treatments may affect men’s future fertility.
- Prior to vasectomy.
- For storing of donor sperm (sperm banking).