Choosing to have a vasectomy is a serious decision because it is carried out with the intention of creating permanent sterility. Our experience with patients over the years has shown that some men who opt for a vasectomy later change their minds about their desire to have children. Reasons for this include death of a spouse, death of a child, divorce, separation, or just changing their minds.
The decision on whether to store sperm as a way to potentially conceive a child in the future is an important one. Conception using stored sperm is not certain, and the necessary medical insemination process can be costly. Cryogenic sperm storage is a good insurance policy, but is not a fully reliable method. If you are concerned to ensure future ability to conceive a child, then the vasectomy itself should be reconsidered.