Semen Analysis

Semen analysis at a glance

  • A semen analysis is typically the first test performed to determine if there is male factor infertility and measures the number and quality of sperm in the semen, as well as other parameters.
  • Male infertility is a contributing factor in roughly 40% of all infertility cases, and issues with sperm health account for the majority of male infertility causes.
  • A semen analysis is the most useful test for male infertility and checks for sperm movement, shape, sperm count and other issues related to both semen and sperm.

What is a semen analysis for male infertility?

According to the American Society for Reproductive Medicine (ASRM), 20% of infertility cases are due solely to male factor infertility and another 20% are caused by a combination of male infertility and another factor. One of the main causes of male infertility is abnormalities in the sperm.

Producing healthy sperm is a complex process, involving several elements that need to work together. The testicles must function properly and in sequence with the pituitary and hypothalamus glands that trigger sperm production. The sperm then has to be transported from the testicles and mixed with semen for ejaculation. Problems in this system can result in sperm of poor quality.

Because male factors play a role in about 40% of infertility cases, men who have concerns should see a specialist for an evaluation.

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A semen analysis can provide information about the sperm and semen that have an effect on male fertility. A study published by the National Institutes of Health shows that a semen analysis can detect 9 out of 10 men with infertility problems.

This test can also help identify if there is an infection in the reproductive system. The results can help determine the appropriate infertility treatments.

Some of the markers this test measures follow.

Sperm count

Typically, there are over 15 million sperm per milliliter of ejaculated semen. Low sperm count, under the 15 million mark, often means there will be more difficulty fertilizing an egg.

Low sperm count is known as oligozoospermia (also called oligospermia), while the complete absence of sperm in semen is called azoospermia. Many things can cause low or no sperm count, including infections, anatomical issues, hormone imbalances, chromosome defects and blockages.

Sperm concentration is different from low sperm count, though the terms are often used interchangeably. Sperm concentration refers to the number of sperm per milliliter in a specific sized sample of the semen, and includes lower limit parameters that indicate fertility issues.

Sperm motility

Motility is the percentage of sperm that move forward in a normal motion. Sperm that travel in a generally straight path are the highest quality. They also move with enough velocity that they have the highest chance of penetrating the outer coating of the egg for fertilization. This test also checks if the sperm are able to move through cervical mucus, fallopian tubes and join with the egg.

Additionally, 50% of sperm should be motile an hour after ejaculation to improve the odds of one or more surviving the difficult journey making it to the egg.

Sperm morphology

Overall health of sperm is determined by its morphology or the shape, cellular properties and size. Sperm with defects such as misshapen heads or bent tails can struggle to fertilize the egg.

Sperm with abnormal morphology could also have DNA damage. Each sperm cell contains two strands of DNA that store information necessary for the embryo to grow appropriately. Damage to the DNA could be caused by chemicals, heat, constriction or other factors. This could raise the chance of implantation failure or miscarriage.

Liquefaction

At the time of ejaculation semen is a thick gel consistency. However, it should become more liquid after approximately 20 minutes. This test measures how long it takes for the liquefaction to occur. If semen takes an abnormally long time to liquefy, it could indicate inflammation of the prostate or the seminal vesicles.

pH

pH is the measurement of the alkalinity (high pH) or acidity (low pH) of the semen. Abnormalities in the pH of semen could result in decreased sperm movement and physiology.

Volume of semen

Typically, there is a range of 1.5 to 5.0 milliliters of sperm in the ejaculated semen. If there is a lower volume of semen, it could indicate that the seminal vesicles are not producing enough fluid or are blocked.

White blood cells

White blood cells should not be present in the semen and could be a sign of something abnormal. White blood cells can weaken sperm by affecting the membrane and impairing movement.


Related Reading: Infertility FAQs

How we perform a semen analysis fertility test for men

Semen is the fluid released by a male during sexual climax, which carries, protects and nourishes the sperm. For the analysis, a sample of semen is collected. Ideally, this sample will be collected at the fertility clinic, but it can also be done at home if delivered to the clinic within an hour of collection.

The semen can be collected through masturbation, without the use of lubricants, including water-based ones, into a sterile container. Alternatively, a special condom can be used during intercourse to collect the semen. A physician may recommend the male not release sperm, or ejaculate, for a few days before providing a sample.

Because sperm levels can fluctuate between tests, the individual may be required to give more than one sample. The same individual giving a sample two weeks apart can expect differences in the semen analysis.

Once delivered to the lab, the semen will be processed and evaluated for certain parameters, and the sperm assessed for volume, concentration, motility and shape.

What if the semen analysis is abnormal?

Since sperm levels fluctuate, repeating a semen analysis is typically recommended in order to get an accurate assessment. If abnormalities are detected in the first analysis and confirmed on the second, a fertility specialist will develop a treatment plan. These individualized plans are based on the reversibility of the cause, severity of the problem and more.

An appointment with a urologist, a specialist dealing with the male reproductive system and urinary tract, may be required depending on the severity of the cause.

Other tests that may be recommended by a fertility specialist or urologist if the semen analysis is abnormal include hormone testing, genetic tests, physical examination and more.