IntroductionInfertility is defined as the failure of a couple to become pregnant after one year of regular, unprotected intercourse. In both men and women the fertility process is complex, and, in many cases, infertility is caused by a combination of problems in both partners that conspire to prevent conception. About 10% to 15% of couples experience some form of infertility, and, in approximately 40% of these cases, male infertility is the major factor. Another 40% of infertility problems are caused by abnormalities of the woman’s reproductive system, and the remaining 20% involve couples who both suffer reproductive difficulties.
Experts suggest that sperm counts tend to fluctuate widely from year to year and also from season to season. Sperm counts appear to differ by region. Temperature and climate may play some role in the differences seen from country to country and from year to year.
Auto AntibodiesAutoimmunity is a condition in which the antibodies of the immune system attack specific cells in the body, mistaking them for micro foreign invaders. In the case of male infertility, such so–called auto antibodies target the sperm. Most commonly, such auto antibodies develop after vasectomy when sperm continue to be produced but, instead of being confined to the reproductive passages, they leak out into the body where the immune system perceives them as foreign invaders and develops antibodies to attack them.
Even if a procedure to reverse the vasectomy is performed, such antibodies often persist. Antibodies to sperm can also appear in men without previous vasectomies and have been reported to be present in 10% of all sub–fertile men. The causes of antibodies in these cases are usually not known. Other Vasectomy–Induced Factors. The important immune factors that trigger the autoimmune process are called leukocytes. Among their other harmful effects is the production of particles called oxygen–free radicals (also called reactive oxygen metabolites), which are particularly injurious to sperm. Vasectomy may also change other factors that affect fertility. Studies report, for instance, that the malfunctioning epididymis after vasectomy reduces normal amounts of a protein called P34H, which is on the surface of the sperm and serves to enhance fertility.