A semen analysis measures the amount of semen a man produces and determines the number and quality of sperm in a semen sample.

A semen analysis is usually one of the first tests done to help determine whether a man has a problem fathering a child. A problem with the semen or sperm affects more than one-third of the couples who seek assisted reproduction services.

Tests undertaken during a semen analysis include:

• Volume: a measure of how much semen is present in one ejaculation.
• Sperm count: a count of the number of sperm present per milliliter of semen in one ejaculation.
• Sperm morphology: a measure of the percentage of sperm that have a normal shape.
• Sperm motility: a measure of the percentage of sperm that can move forward normally.