Sperm in the testes and duct system are normally isolated from the body’s immune system. When a vasectomy is performed, the sperm are exposed to the immune system, and the body responds as if the sperm were a foreign protein. The immune system produces substances called antibodies against the sperm.
These antibodies may be found in the blood and on the surface of the sperm in most men after vasectomy, but generally disappear after about 6 months. In some men, however, they may remain elevated for a prolonged time.
Many infertility specialists believe these persistent sperm antibodies may cause fertility problems after a vasectomy is reversed. However, not all men with elevated sperm antibodies have problems with fertility, and other men with low or absent antibody levels are unable to achieve pregnancy. Furthermore, successful reversal should reduce the levels of sperm antibodies, through precise alignment of the duct system, eliminating exposure of the sperm to the immune system.
At this time, therefore, the role of sperm antibodies remains under investigation. Routine testing of sperm antibodies prior to surgery is not recommended, since it is expensive, and does not predict the chances for pregnancy with sufficient reliability.
In Dr. Finnerty’s opinion, persistent high sperm antibody levels after vasectomy reversal often suggest persistent partial obstruction or inaccurate alignment of the vas or epididymis reconstruction, leading to ongoing sperm exposure to the immune system.
