Normally, our bodies develop antibodies to help protect our immune system against illnesses. However, sometimes our bodies develop antibodies to the wrong thing, which can cause negative repercussions. Among infertile men, about 10% will be diagnosed with having antisperm antibodies, a condition that can significantly decrease your chances of pregnancy.
Normally, the testes contain a natural barrier, known as the blood-testes barrier. This barrier acts a protective layer that prevents immune cells from being able to access sperm within the male reproductive tract. Yet, this barrier can be broken, through injury to the reproductive tract, thereby allowing the immune cells to come into contact with the sperm.
Once the barrier is broken, immune cells are able to detect the presence of sperm due to their unique antigen surface. This triggers a response by the immune system to treat sperm as an "invader" and attack it. Antibodies then attach themselves to different parts of the sperm and interfere with male fertility in a number of ways.
Antibodies that are located on the tail of sperm can cause the sperm to become immobilized or clump together. When antibodies are found on the head of sperm, they can prevent the sperm from being able to efficiently make its way through a woman’s cervical mucus to the egg. However, it is also possible for a woman to develop antisperm antibodies in her cervical mucus, which will only serve to hinder attempts at conception even more. It is thought that antisperm antibodies in cervical mucus could account for as much as 40% unexplained infertility cases.
Sperm that does manage to make it to the egg can have a difficult time properly binding and fertilizing the egg due to antibodies attached to its head.
Reasons for Antisperm Antibodies
There are numerous reasons why the natural barrier between sperm and the immune system can be broken causing antisperm antibodies to form. Some of these factors include:
- Injury to the testicles
- Undescended testicles
- Twisting of the testicles
- Testicular cancer
- Testicular biopsy
Additionally, men who have undergone a vasectomy reversal are particularly prone to developing this fertility problem. Close to 70% of men who have had their vasectomy reversed will develop antisperm antibodies.