Decreased levels of the sex hormone testosterone can affect the amount of sperm a man is able to produce. Age plays a large role in testosterone and sperm production; however, sperm production can be maintained well into old age.
According to MayoClinic.com, low sperm count, also known as oligospermia, occurs if there is less than 20 milliliters of sperm in each milliliter of semen. In many cases, low sperm count is identified when a couple is unable to conceive a child after one year of having unprotected sex. If decreased testosterone, also known as male hypogonadism, is the cause, according to MayoClinic.com, this can be identified by a low sex drive, erectile dysfunction, less body hair or tenderness in the testicles.
According to MayoClinic.com, decreased testosterone can occur during fetal development, puberty or adulthood. If testosterone is lowered during adulthood, a man may be unable to have children and he may have erectile dysfunction. Men will often produce less testosterone as they age. According to the Cleveland Clinic, testosterone production is reduced 20 percent in men over 60 years old and reduced 30 to 40 percent in men over 80. Andropause, the male version of menopause, is the cause of lowered testosterone in older men.
There are two types of hypogonadism: primary and secondary. According to MayoClinic.com, primary hypogonadism originates in the testicles and the secondary version occurs in the areas of the brain that tell the testicles to produce testosterone, the hypothalamus or pituitary gland. Some primary hypogonadism could be caused by an injury to the testicle, aging, Klinefelter's syndrome or alcohol use. According to the Cleveland Clinic, if a person has a pubertal delay or a brain tumor, these could be the cause of secondary hypogonadism. Aging could also cause secondary hypogonadism.
Testosterone replacement therapy can increase the production of testosterone. However, according to Dr. Michael A. Werner of Andropausespecialist.com, since testosterone is being given from the outside, the testicles will stop producing their own testosterone, which will temporarily or permanently stop sperm production. If you are trying to start a family, it is still possible to have a baby with a low sperm count even if it takes longer than a year; however, if you are no longer producing sperm, you will be unable to naturally get a woman pregnant. According to Medline Plus, pituitary hormone injections, surgery or radiation therapy can help male patients produce sperm.
According to the Cleveland Clinic, ductal disease, epididymal hostility, erectile dysfunction and ejaculatory dysfunction can also cause decreased sperm production. Chemotherapy drugs used to fight cancer can also decrease your sperm count. To determine the cause of your decreased sperm production, contact your doctor to have your testosterone levels tested. If decreased testosterone is not the cause, your doctor will perform additional tests.