A vasectomy is a surgical procedure performed for the purpose of preventing the release of sperm when a man ejaculates. It is a sterilization process for men. It is considered to be a permanent form of birth control. The process involves sealing off the vas deferens from each testicle so that the sperm cannot become mixed with the man's semen. Sperm production continues in the testicles and the sperm are absorbed into the body. It can take 10 - 20 ejaculations for the patient's sperm count to reach zero. In the meantime, back up birth control is advised.