A vasectomy is a surgical procedure performed as a method of birth control. It involves cutting the vas deferens (pronounced VAS DEF-uh-renz) in order 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 (pronounced ep-i-DID-uh-mis). 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 (pronounced yoo-REE-thruh) 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