Male Infertility – Low Sperm Count, Sperm Motility

Sperms defects or disorders are the most common causes of male infertility. The vast majority of cases of male infertility are due to a low sperm count (around 70% of cases). Often poor motility and a high rate of abnormal sperms are associated with a low sperm count. There are many reasons for sperm defects including hormonal imbalances, testicular varicocele and infections often a definite cause cannot be found.
When no sperm whatever are found in the semen, testicular failure or failure to ejaculate may be the cause. Testicular failure may be result of an injury, a late complication of mumps, or damage to the blood supply to the testicle. Alternatively, the problem may've a hormonal cause, with the pituitary gland failing to stimulate the testes to produce sperm.
The inability of the testes to produce sperm, despite hormonal simulation, can be caused by undescended testes, cellular defects within the testes and congenital chromosomal abnormalities such as Klinefelter's syndrome.

Tubal damage caused by infectionscan prevent the sperm from getting into the semen as can retrograde ejaculation where the sperm passes into the bladder instead of being released through the penis into the vagina.

Immunological disorders

A very small percentage of men suffer from Immunological disorders that can cause them to produce antibodies against their own sperm. This is the result of an autoimmune response to surgical interference, trauma or infection that is thought to be responsible for 10% of unexplained male infertility. The cause of this phenomenon however remains partly unclear.