The most prevalent cause of testicular infertility is maturation arrest. This is a halt at some stage of spermogenesis.
Most patients are either azoospermic or oligospermic.
The second most prevalent cause of testicular infertility is Hypospermia. This is when all cell types are present in approximately the usual form, but the number of each is decreased. This does complete itself unlike maturation arrest. It is also a oligospermic disease. The main characteristic of Sertoli Cell-syndrome consist of testicular tubes that show a moderate decrease in diameter and are void of germ cells.