Understanding Infertility

Estimates indicate that approximately 40% of all infertility is the result of a male factor, most commonly related to the quality and quantity of sperm.

Assessing the causes

Investigations carried out by a family doctor or specialist can provide a clear diagnosis of male infertility in most cases, although no test can predict fertility potential with total accuracy. Because the sperm characteristics required for 'normal' fertilization are well known, any abnormal results from a sperm test will suggest a male problem. These tests, which are carried out on a semen sample can reveal abnormalities in sperm numbers, movement and shape.

In recent years, fertility clinics have also used in-vitro fertilization (IVF) as a diagnostic test. Often, healthy eggs fail to fertilize in the laboratory because of abnormal sperm function. Failed IVF, therefore, can provide more conclusive evidence of 'male factor' infertility.

Abnormal semen analysis

One or more of the following factors may be identified as a cause for male infertility in the case of an abnormal semen analysis.

• Low sperm count Normally men produce at least 20 million sperm per millilitre of semen. Fewer is judged to be impaired fertility
• Non-production of sperm The result of testicular failure or a complete absence of sperm, perhaps due to an obstruction
• Poor sperm motility Sperm are unable to travel through the cervix to meet the egg in the fallopian tube
• Poor morphology (shape) An individual sperm is unable to penetrate the outer layer of an egg