A vasectomy is a form of birth control for men. This minimally invasive surgical procedure prevents sperm from entering the semen and then being released during ejaculation.

According to the Centers for Disease Control and Prevention (CDC), a vasectomy is a minor surgery to cut or seal the vas deferens — the tube that connects the testes to the penis. Because sperm cells are produced in the testes, they can no longer be transported into the semen and therefore cannot cause pregnancy.

An estimated 500,000 men have a vasectomy every year in the United States, according to the Cleveland Clinic. Many men consider having a vasectomy when they are certain they do not want any more children or do not want children at all.

Dr. Hussain Alnajjar, a consultant urological surgeon at University College London Hospital in the U.K. and honorary associate professor at University College London, said that a vasectomy is the most reliable method for male sterilization. "It should also be regarded as irreversible," he told Live Science in an email. "Vasovasostomy procedure, often referred to as vasectomy reversal, is possible, but it may not always be successful."

How does a vasectomy work?

The procedure doesn't affect a man's ability to perform sexually or achieve orgasms and it doesn't visibly change semen, said Dr. Paurush Babbar, a urologist at The Urology Group in Cincinnati, Ohio, and a member of the American Urological Association.