Vasectomy is a simple operation that makes a man sterile, or unable to father a child.
The procedure blocks or cuts the tubes that carry sperm from the testicles. After vasectomy, sperm cannot be mixed with semen, which is the fluid a man ejaculates during orgasm. Semen is not made in the testicles, and vasectomy doesn’t affect the semen or how it is ejaculated. It’s just that, after vasectomy, a man’s semen contains no sperm, so he cannot make a woman pregnant.