Also Known As
Sperm analysis
Sperm count
Seminal fluid analysis
Formal Name
Semen analysis
This article was last reviewed on
This article waslast modified on 15 May 2024.
At a Glance
Why Get Tested?

To investigate to see if there is a problem with your fertility. This is often performed if you are in a heterosexual relationship and your partner is having trouble becoming pregnant.

It is also necessary after a vasectomy operation to ensure that the sterilisation operation was successful and that you are no longer fertile. This test is called a post-vasectomy semen analysis (PVSA).

When To Get Tested?

Semen analysis - When you think you might have a fertility problem. This is usually undertaken one year after trying to conceive with natural intercourse.

Post-vasectomy semen analysis – 12 weeks after the vasectomy with at least 20 ejaculations since the operation.

Sample Required?

A semen sample collected in a sterile container provided by the laboratory or doctor. It is important that the specimen container has been tested to ensure it is not toxic to sperm.

Test Preparation Needed?

In order for the test to be reliable, you may need to abstain from masturbation or sex for two to seven days before the sample is collected. You should follow the instructions given to you by the laboratory or your doctor.

On average it takes 7 working days for the blood test results to come back from the hospital, depending on the exact tests requested. Some specialist test results may take longer, if samples have to be sent to a reference (specialist) laboratory. The X-ray & scan results may take longer. If you are registered to use the online services of your local practice, you may be able to access your results online. Your GP practice will be able to provide specific details.

If the doctor wants to see you about the result(s), you will be offered an appointment. If you are concerned about your test results, you will need to arrange an appointment with your doctor so that all relevant information including age, ethnicity, health history, signs and symptoms, laboratory and other procedures (radiology, endoscopy, etc.), can be considered.

Lab Tests Online-UK is an educational website designed to provide patients and carers with information on laboratory tests used in medical care. We are not a laboratory and are unable to comment on an individual's health and treatment.

Reference ranges are dependent on many factors, including patient age, sex, sample population, and test method, and numeric test results can have different meanings in different laboratories.

For these reasons, you will not find reference ranges for the majority of tests described on this web site. The lab report containing your test results should include the relevant reference range for your test(s). Please consult your doctor or the laboratory that performed the test(s) to obtain the reference range if you do not have the lab report.

For more information on reference ranges, please read Reference Ranges and What They Mean.

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 spermatozoa (sperm).

Semen is the turbid, whitish liquid that contains sperm and the products from several glands. It is normally fairly thick after ejaculation and then becomes thinner within ten to thirty minutes. Sperm are the 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 should be progressively motile (can move forward independently) and this allows them to travel to and fuse with the female’s egg, resulting in fertilisation. In each semen sample, there should be millions of sperm and varying amounts of other substances that support fertilisation.

A typical semen analysis could measures:

  • Volume of semen
  • Consistency (thickness) of the semen
  • Sperm concentration
  • Total number of sperm
  • Sperm motility (the percentage that are able to move, as well as how vigorously and progressively the sperm move)
  • Number of normal-shaped and not normal-shaped (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 antisperm antibodies. If assisted reproductive technology is contemplated, e.g. in vitro fertilisation (IVF), sperm function tests may also be performed.

How is the sample collected for testing?

Most laboratories require samples to be collected at the hospital as the semen needs to be examined within one hour after ejaculation for a fertility semen analysis. Semen is collected in a dedicated private area with a locked door. The man masturbates and collects the semen in a sterile specimen container.

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 man should ask doctor to provide a silastic condom which is specifically made to be non-toxic to sperm. Do not use standard condoms as these are usually spermicidal.

Sperm are very temperature sensitive. If the sample is collected at home, the sample should be kept next to the body during transportation. It should not be left at room temperature and should not be refrigerated or heated. The sample must be delivered to the lab within one hour for analysis.

Is any test preparation needed to ensure the quality of the sample?

In order for the test to be reliable, you need to abstain from masturbation or sex for two to seven days before the sample is collected. You should follow the instructions given to you by the laboratory or your doctor. You should not collect the sample via intercourse or oral stimulation, as this can contaminate the sample. The penis and genitals should be thoroughly cleaned, rinsed and dried before sample production. No lubricants should be used, as these can be toxic to sperm.

Accordion Title
Common Questions
  • How is it used?

    Semen analysis is used to determine whether a man might be infertile (unable to get a woman pregnant). The semen analysis looks at many aspects of the semen and sperm. Semen analysis to determine fertility should be performed on a minimum of two samples at 3 months apart, because sperm count and semen consistency may vary from day to day and some conditions, e.g. the common cold, can temporarily affect sperm levels.

    The semen analysis can also be used to count sperm after a man has a vasectomy. If there are still sperm present in the semen, the man and his partner will have to take precautions so that his partner will not become pregnant. He will have to return for one or more sperm counts until the sperm are cleared from his sample(s).

  • When is it requested?

    There are two main reasons for semen analysis.

    Following vasectomy: Semen analysis is recommended following a vasectomy to make sure that the sterilisation operation has been successful.

    Testing for infertility: Semen analysis is performed when your doctor thinks that you might have a fertility problem. About one in six couples experience problems conceiving. Male infertility is on the increase and male factors are implicated about 50% of the time. Male infertility has many causes and some of these can be treated successfully. If male factors are the cause, analysis of the semen is necessary to determine what is preventing fertility and to evaluate whether assisted reproductive technology (e.g. IVF) would be helpful. If sperm are suboptimal, a form of IVF called ICSI (intracytoplasmic sperm injection) can be used, whereby a single sperm is carefully injected directly into the woman’s egg to cause fertilisation. When a semen analysis is abnormal, your doctor may ask for one or more repeat tests.

  • What do the test results mean?

    The typical volume of semen collected is around a half to one teaspoonful (1.4 millilitres) of fluid. Less semen might indicate a possible blockage or retrograde (backwards) ejaculation. The semen should initially be thick and then become thinner within thirty minutes. If this does not occur, the viscosity may reduce sperm movement.

    Sperm concentration is measured in millions of sperm per millilitre of semen. The normal count is 16 million sperm or more per millilitre. Fewer sperm and/or a lower sperm concentration may reduce fertility and therefore the chance of pregnancy. Following vasectomy, the goal is to have no sperm detected in the semen sample.

    The percentage of moving sperm in a sample is known as its 'motility'. The rate and direction of travel of the sperm is also assessed. At least 30% of sperm should be progressively motile up to one hour after ejaculation. The progression of the sperm is rated from 1 to 4 with 3-4 indicating good motility. If less than half the sperm are motile, a stain is used to identify dead sperm. This is called a 'sperm vitality test'.

    Morphology analysis is the study of the size, shape, and appearance of the sperm cells. The analysis evaluates the structure of 400 sperm, and any defects are noted. The more abnormal sperm that are present, the lower the likelihood of fertility.

    Semen pH should be between 7.2 and 7.8, fructose between 150-600 mg/dL, and there should be fewer than 1 million white cells per mL.

  • Is there anything else I should know?

    Common causes of male infertility include reduced testicular function (failure of the testicles to produce enough sperm) and obstruction of the tubes that carry semen to the penis.

    When a doctor is evaluating a man's fertility, each aspect of the semen analysis is considered, as well as the findings as a whole. Each part of the semen analysis either contributes to fertility or lessens it, but the results do not necessarily predict the eventual outcome. Couples with poor results may still conceive, with or without assistance, and those with apparently good results may experience difficulties.

    Several factors can affect the sperm count and other semen analysis values. A man may have a lower sperm count if he has damage to the testicles, has gone through radiation treatment of his testicles, or has had exposure to certain drugs (such as azathioprine, cimetidine, and some cancer chemotherapy drugs). A man with a higher level of oestrogens may have a lower sperm count.

  • What are the best indicators of fertility in a semen analysis, out of all of the many things that are checked?

    Sperm count (number of sperm), sperm motility (movement of sperm) and sperm morphology (normal shape of the sperm) are most closely linked with fertility rates.

  • I had good motility on my first sperm sample, but later it was very low. What could cause that?

    Delay in getting the specimen to the laboratory can affect motility. However, if the specimen has been examined within an hour of ejaculation, there may be other reasons such as a genital infection or an inflamed prostate gland.

  • Shouldn't they check my wife's fertility first?

    When a couple cannot become pregnant, it is much easier, less invasive, and less expensive for the man to be tested first. A man requires only semen analysis, and the samples can be collected and a male cause of infertility confirmed or ruled out very quickly. If the man’s semen is normal, then it makes sense to move ahead with the more invasive and expensive tests for female infertility.