The sperm count is a measure of fertility in a man. It is the number of sperm in a unit volume of semen. A normal sperm count is between 20 million and 150 million sperm per millilitre A sperm count below 20 million sperm per millilitre is low and may indicate a fertility problem. [http://www.mothersbliss.co.uk/planning/low.asp.

Having a man's sperm count measured is a common method for diagnosing problems in couples experiencing fertility problems. It is important to note that although a man's sperm count may be less than the normal range, it is still possible to father a child.

Fertility medicine | Andrology