Vasectomy is a surgical operation for men. Pregnancy cannot happen when sperm cannot reach an egg. Of every 1,000 women who are sterilized, only five will become pregnant during the first year. About one out of 100 women will become pregnant each year after. Of every 1,000 men who are sterilized, fewer than two will cause pregnancy during the first year.
Sterilization provides no protection against sexually transmitted infections.
Vasectomy is not. Some sperm remain in a man's system after the operation. Other birth control must be used until the sperm are used up. This usually takes at least 15 ejaculations. Vasectomy is less expensive.