This is a commonly thought of question among men considering vasectomy. When a vasectomy is performed, the millions of sperm cells made every day in the testicles continue to be produced. Where do they go? What happens to them? Even in men who have not had a vasectomy, approximately 80% of the sperm cells never make it out of the testicles into the semen. They actually undergo a process called apoptosis, which is a programmed cell death. The supporting cells around them gobble them up and digest them. This is thought to be so the less “fit” sperm for fertilization and pregnancy don’t make it out in as great of numbers. That being said, after a blockage is made so sperm cannot get out into the semen with a vasectomy, the testicles are well prepared to dispose of the sperm cells and the production just continues. That is why vasectomy reversals work, the testicles do not stop making sperm after a vasectomy, they just cannot get out.