Male infertility refers to the inability of a male to achieve a pregnancy in a fertile female. In humans it accounts for 40-50% of infertility. Male infertility is commonly due to deficiencies in the semen quality.
Pre-testicular factors refer to conditions that impede adequate support of the testes and include situations of poor hormonal support and poor general health including :
Testicular factors refer to conditions where the testes produce semen of low quantity and/or poor quality despite adequate hormonal support :
Post-testicular factors decrease male fertility due to conditions that affect the male genital system and include defects of the genital tract as well as problems in ejaculation. Here the testicular sperm production is normal :