Semen after a vasectomy is virtually unchanged. Although the path of sperm is blocked off after this operation, men still ejaculate the same amount of semen as they would have prior to surgery. The only difference is that there will no longer be sperm found inside of this semen.
During a vasectomy the vas deferens, or tube leading from the testicles to the tip of the penis, is blocked off at the entrance so that sperm cannot move through. Since semen is generally not added to the sperm until it has traveled up this tube further, semen is not blocked from exiting. This allows a man to function sexually and ejaculate normally.
Sperm are still created by the testicles after surgery, and are then absorbed into the body. Semen after a vasectomy exits as usual. It may still contain sperm which was already present in the vans deferens prior to surgery for several months after the operation. For this reason, couples are encouraged to use a backup method of birth control until it is confirmed that the male is sterile.
To determine the sterility of semen after a vasectomy, it is tested at set intervals to get a sperm count. In the beginning, several thousand sperm cells may still be found. This number should get smaller with each check until the count finally makes it to zero. In some cases the vasectomy may not have been successful. If the tube is not blocked off correctly, sperm may still be able to get through.
Although sperm count within semen after a vasectomy should be zero, occasionally the tubes can grow back together without a man’s knowledge. This means that he may be able to impregnate his partner during intercourse. A man may also be able to have his vasectomy reversed. The success of a such an operation varies widely from person to person.
Vasectomies are relatively routine operations and there are generally not long-term side effects aside from sterility. Soreness may occur for a day or so after the surgery is performed, but this is generally mild and subsides quickly. Although rare, there are risks with any operation. These can include a negative reaction of local anesthesia, and swelling of the testes. Very rarely, the sperm which are reabsorbed into the body after a vasectomy may cause an allergic reaction.