A vasectomy is a surgical procedure performed as a method of birth control. It involves cutting the vas deferens to close off the tubes that carry sperm from the testicles (there is one vas deferens per testicle). If a man has a successful vasectomy, he can no longer get a woman pregnant.1
Sperm are made in the two testicles, which are inside the scrotum. Sperm is stored in a tube attached to each testicle called the epididymis. When a man ejaculates, the sperm travel from the epididymis, through the vas deferens, and then mix with seminal fluid to form semen. The semen then travels through the urethra and out the penis.
Before a vasectomy, semen contains sperm and seminal fluid. After a vasectomy, sperm are no longer in the semen.2 The man's testicles will make less sperm over time, and his body will harmlessly absorb any sperm that are made.3