At a Glance
Why Get Tested?
To learn about the health of your reproductive organs, particularly if your partner is having trouble becoming pregnant, or after a vasectomy to determine if the operation was successful
When to Get Tested?
When you think you might have a fertility problem or after you have had a vasectomy
A semen sample collected in a sterile, wide-mouth container provided by the lab
Test Preparation Needed?
Follow carefully instructions that are provided to you for sample collection.
The Test Sample
What is being tested?
A semen analysis measures the quantity and quality of the fluid released from the penis during ejaculation. It evaluates both the liquid portion, called semen, and the microscopic, moving cells, called sperm.
Semen is a viscous, whitish liquid that contains sperm and the products from several glands. It is normally fairly thick after ejaculation and then thins, liquefying within 10 to 30 minutes. Sperm are reproductive cells in semen that have a head and a tail. Each sperm contains one copy of each chromosome (all of the male's genes). Sperm are motile, normally moving forward through the semen. Inside a woman's body, this property enables them to travel to and fuse with the female's egg, resulting in fertilization. In each semen sample, there are millions of sperm and varying amounts of fructose, buffers, coagulating substances, lubricants, and enzymes that are intended to support the sperm and the fertilization process.
A typical semen analysis measures:
- Volume of semen
- Consistency (thickness) of the semen
- Sperm concentration (density)
- Total number of sperm
- Sperm motility (percent able to move as well as how vigorously and straight the sperm move)
- Number of normal and not normal (defective) sperm
- Coagulation and liquefaction
- Fructose (a sugar in semen)
- pH (acidity)
- Number of immature sperm
- Number of white blood cells (cells that indicate infection)
Additional tests may be performed if semen is abnormal, such as a test for sperm antibodies. If assisted reproductive technology such as in vitro fertilization is contemplated, sperm function tests may also be performed. Sometimes a test called cryosurvival is done to see how well semen will survive for long-term storage if a couple would like to store sperm for future pregnancies.
How is the sample collected for testing?
Most laboratories require samples to be collected on-site as the semen needs to be examined within one hour after ejaculation. Semen is collected in a private area, usually a bathroom. The man masturbates and collects the semen in a jar. Some men, for religious or other reasons, might want to collect semen during the act of intercourse, using a condom. If this is the case, the doctor should provide the condom or sheath because lubricated condoms can affect test results. Sperm are very temperature-sensitive. If collection is done at home, the sample should be kept next to the body during transportation. It should not be left at room temperature for an extended period of time and should not be refrigerated or heated.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
To give sperm a chance to replenish, a man should abstain from ejaculating for two to four days before the sample is collected. Follow the instructions that are provided to you.
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
Sources Used in Current Review
Pagana, K. D. & Pagana, T. J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 843-845.
Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 978-979.
Dugdale III, D. (Updated 2008 May 21). Semen Analysis. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003627.htm. Accessed February 2010.
Rubenstein, J. and Brannigan, R (Updated 2008 March 26). Infertility, Male. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/436829-overview through http://emedicine.medscape.com. Accessed February 2010.
Bayrak-Toydemir, P. et. al. (Updated 2009 August) Infertility. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/Infertility.html# through http://www.arupconsult.com. Accessed February 2010.
Rebar, R. (Revised 2008 November) Infertility, Sperm Disorders. Merck Manual for Healthcare Professionals [On-line information]. Available online at http://www.merck.com/mmpe/sec18/ch256/ch256b.html?qt=semen analysis&alt=sh through http://www.merck.com. Accessed February 2010.
Sources Used in Previous Reviews
Clinical Guide to Laboratory Tests (third edition), Norbert W. Tietz, editor. Philadelphia: W.B. Saunders & Co., 1995; Pp. 554-556.
Laboratory Tests & Diagnostic Procedures with Nursing Diagnoses (4th edition), Corbett, JV. Stamford, Conn.: Appleton & Lang, 1996. Pp. 727-728.
Robert Harr, M.S. MT(ASCP). Associate Professor and Chair, Department of Public and Allied Health; Program Director, Medical Technology, Bowling Green State University.
Larry J. Kricka, PhD. American Association for Clinical Chemistry, past President. University of Pennsylvania Medical Center, Philadelphia, PA.