Sperm can be frozen indefinitely. There have been normal pregnancies from sperm stored frozen for 12 years. The efficacy of the freezing is questionable when it has been frozen for more than 12 years. Each individual’s sperm reacts differently to the freezing process. The result of the thawed test batch can give you some indication of how your sperm reacts to the process.
If you are wondering if insemination with thawed sperm increases the birth defects or leads to abnormal children, click here.
If you seeking a sperm donation, or are a prospective donor, here is a list of sperm banks by location.