Semen Analysis

Overview

What is semen?

This substance is released from a man’s penis when he has an orgasm (ejaculates). It contains:

Sperm, male reproductive cells. The cells have a unique shape that contain:

  • Head, which includes genetic material (DNA) to fertilize a woman’s egg.
  • Tail that helps it travel (“swim”) through a woman’s reproductive system to reach the egg and fertilize it.

Fluids, which make it possible to deposit sperm toward the back of a woman’s vagina. This area is close to the cervix, which is the opening of the womb, where babies develop.

Proteins, vitamins and minerals that fuel the sperm’s journey to the egg.

What is a semen analysis?

A semen analysis is a lab test that examines a sample of semen under a microscope. It evaluates things such as sperm count, activity (motility) and shape (morphology).

Who needs a semen analysis?

Reasons you may need a semen analysis include:

Male infertility: If a couple has been having difficulty trying to conceive, there may be a semen abnormality. In some cases, it’s due to an issue with a man’s sperm. A semen analysis evaluates the likelihood that a man can cause a pregnancy.

Vasectomy follow-up: A semen analysis determines whether a vasectomy was successful. This procedure blocks the tubes that deposit sperm in semen. If there are no sperm in the semen, the vasectomy worked, and a man cannot get a woman pregnant.

Test Details

How does a semen analysis work?

A man masturbates to produce a semen sample. This is the preferred method because it provides a clean sample. Since sperm counts vary from day to day, you may need to provide more than one sample spaced out a few weeks apart.

Healthcare providers use research-based methods to handle and test the semen. Going to a lab that specializes in semen analysis ensures you receive accurate results.

This includes labs that:

  • Are part of a fertility clinic.
  • Perform a high volume of semen analyses.

What does the analysis look at?

A post-vasectomy semen analysis checks to see whether the semen contains sperm.

  • Normal results would show no sperm or very few non-moving sperm.
  • Abnormal results would contain moving sperm or high numbers of non-moving sperm.

When used as a fertility test in men, it looks at:

  • pH level: Whether semen is too acidic, which can affect sperm health.
  • Semen volume: Amount of semen in the sample (in millimeters).
  • Sperm concentration: Number of sperm per millimeter of semen.
  • Sperm morphology: Size and shape of the sperm.
  • Sperm motility: Ability of the sperm to swim toward an egg.
  • Time to liquefaction: How quickly semen changes from a sticky substance to a liquid.
  • Vitality: Percent of live sperm in the sample.
  • White blood cells: A sign of infection or inflammation.

How do I prepare for a semen analysis if it’s used for fertility testing?

You will need to abstain from sexual activity for two to seven days. This includes intercourse and masturbation. Doing so ensures sperm counts are at their highest level, so you receive a thorough analysis.

How do I prepare for a post-vasectomy semen analysis?

This test is done after a vasectomy is performed, usually 8 to 12 weeks later. It’s helpful to masturbate several times after your vasectomy. This helps clear sperm from from your system. You may be able to provide a semen sample at home and then bring it to the lab.

How do I provide a semen sample to check fertility?

Providing a sample by masturbating is the preferred method. This usually takes place in a lab in a private, comfortable room. You put the sample into a sterile, wide-mouthed container.

If you are not able to masturbate due to religious reasons, you still have options. Your healthcare provider may give you a nonlubricated condom to use during intercourse.

Results and Follow-Up

What do results look like for post-vasectomy semen analysis?

After a vasectomy, it can take several weeks for semen to become sperm-free (azoospermia) or have very few non-moving sperm. You should use backup birth control, like condoms, until you have a test with the desired result.

What do results look like for male fertility testing?

The lab compares the characteristics of your semen to expected values. Your semen should contain:

  • Active sperm, each with a single round head and tail.
  • A certain number of sperm.
  • Have a pH that’s not too acidic.
  • Fluid that turns to liquid in a short amount of time so it can travel through a woman’s reproductive system.

What do abnormal results mean for my ability to help a woman conceive?

Abnormal results mean that you have a below-average chance of getting a woman pregnant. But a semen analysis is not the only factor in evaluating male infertility.

Extra testing is often needed to learn more. These tests may confirm or rule out:

  • Blockages that prevent the body from releasing sperm into semen.
  • Infection.
  • Low sperm count.
  • Low testosterone or hormone abnormalities.
  • Side effects of medications or other medical issues.

A note from Cleveland Clinic

A semen analysis is a lab test that evaluates sperm count, motility, morphology and more. It can be a fertility test in men or confirm that a vasectomy was successful. For accurate results, follow instructions and provide a clean sample. Abnormal results often mean that more testing is necessary. It’s common to repeat the test to confirm your results or determine the next steps of your evaluation.

Last reviewed by a Cleveland Clinic medical professional on 04/30/2021.

References

  • American Society for Reproductive Medicine. Sperm Morphology (Shape): Does It Affect Fertility? (https://www.reproductivefacts.org/news-and-publications/patient-fact-sheets-and-booklets/documents/fact-sheets-and-info-booklets/sperm-morphology-shape-does-it-affect-fertility/) Accessed 4/16/21.
  • Centers for Disease Control and Prevention. Infertility FAQs. (https://www.cdc.gov/reproductivehealth/infertility/index.htm) Accessed 4/16/21.
  • Eunice Kennedy Shriver National Institute of Child and Human Development. How Common Is Male Infertility, And What Are Its Causes? (https://www.nichd.nih.gov/health/topics/menshealth/conditioninfo/infertility) Accessed 4/16/21.
  • MedlinePlus. Semen Analysis. (https://medlineplus.gov/lab-tests/semen-analysis/) Accessed 4/16/21.
  • Sunder M, Leslie SW. Semen Analysis. (https://www.ncbi.nlm.nih.gov/books/NBK564369/) [Updated 2020 Nov 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Accessed 4/16/21.

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