M.D. A recent issue of Human Reproduction Update has a series of articles showing that infection is the most common cause of male infertility and that standard tests for infertility often do not find the infection. When evaluating a male for infertility, doctors check sperm count and sperm mobility. If a man's ejaculate contains fewer than 50 million sperm, he is infertile, and the most common cause of reduced sperm count is infection.
Infection is also the most common cause of inactive sperm.
Doctors don't have a dependable way to measure other causes of infertility such as changes in the sperm membrane and DNA content. These studies stressed that prostate and urinary tube infections that are allowed to continue for several months or years can cause permanent infertility. Because infections are the most common known cause of infertility and the only way to cure these infections is to treat both partners, it may be reasonable to treat all infertile couples with doxycycline or Zithromax for several weeks. FH Comhaire, AMA Mahmoud, CE Depuydt, AA Zalata, AB Christophe. Infections in the male genital tract and reactive oxygen species.