Causes of male infertility can be divided into two categories-
      1- physical abnormalities of the male reproductive tract, such as epididymal or vas obstruction causing impaired sperm production
      2- abnormalities of the sperm themselves.
    However in most cases of male infertility the cause is unknown. semen analysis is done to assess male fertility where we test the number, activity and shape      of the sperm. A normal assessment should show a sperm count of more than 15 million sperm per milliliter with at least 32% of the sperm actively moving          and more than 4% of the sperm of normal shape. They must be capable of moving through the female genital tract to reach the fallopian tube where the egg      is fertilized, and so must survive for a period of 24-48 hours. Common male infertility problems are due to the following:-

       • Abnormal sperm parameters-Oligozoospermia -decreased sperm count Asthenozoospermia- decreased motility

       • Azoospermia .-nil sperms

       • Antisperm antibodies