Infertility in Men - Causes

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Highlights	Diagnosis	Resources
Introduction	Treatment	References
Causes	Assisted Reproductive Technologies	Resources
Risk Factors	Lifestyle Changes	References

A semen analysis will provide information on:

Amount of semen produced (volume)
Number of sperm per milliliter of semen (concentration)
Total number of sperm in the sample (count)
Percentage of moving sperm (motility)
Shape of sperm (morphology)

Semen Volume and Concentration. The seminal fluid (semen) itself is analyzed for abnormalities. The color is checked and should be whitish-gray.

The amount of semen is important. Most men ejaculate 2.5 - 5 milliliters (mL) (1/2 - 1 teaspoon) of semen. Either significantly higher or lower amounts can be a sign of prostate problems, blockage, or retrograde ejaculation.

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The semen will be tested for how liquid it is. Abnormal results may suggest prostate gland problems or lack of sperm.

The amount of sugar (fructose) in sperm will be measured:

Since fructose is added to the semen in the epididymis, an absence of fructose indicates that an obstruction has occurred either in the vas deferens or the epididymis.
Conversely, if there is fructose in the semen but no sperm, then the channel from the epididymis is open but there is a defect in sperm production.

Other factors may also be measured:

White blood cell counts are taken to detect infection.
Low levels of a substance called inhibin B, which appears to be produced only in the testes, may indicate blockage or other defects in the seminiferous tubules.
Low levels of another compound, alpha-glucosidase, may also indicate blockage in the epididymis.

Sperm Count. A low sperm count should not be viewed as a definitive diagnosis of infertility but rather as one indicator of a fertility problem. In general, a normal sperm count is considered to be 20 million per milliliter of semen.

Sperm Motility. Motility (the speed and quality of movement) is graded on a 1 - 4 ranking system. For fertility, motility should be greater than 2.

Grade 1 sperm wriggle sluggishly and make little forward progress. (Sperm that, in fact, clump together may indicate that antibodies to the sperm are present.)
Grade 2 sperm move forward, but they are either very slow or do not move in a straight line.
Grade 3 sperm move in a straight line at a reasonable speed and can home in on an egg accurately.
Grade 4 sperm are as accurate as Grade 3 sperm, but move at a very rapid speed.