Semen Analysis: Information & Specialists in Semen Analysis

A semen analysis is the result of an examination of a man’s seminal fluid (ejaculate). The ejaculate is evaluated against various reference values established by the World Health Organization (WHO). The goal is to assess the man’s fertility.

These reference values are globally recognized guidelines for assessing and comparing the quality and quantity of sperm contained in the ejaculate.

The ejaculate is examined for various parameters. These include, for example,

• the volume (amount) and pH level of the ejaculate,
• sperm concentration,
• sperm motility (movement),
• morphology (external shape), and
• vitality (liveliness).

Causes of male infertility can include, for example,

• insufficient quality or
• a low sperm concentration

.

There are various reasons for having a semen analysis performed. Often, it is the inability to conceive that prompts couples to have their fertility assessed. After one to two years without a pregnancy, it is appropriate to see a doctor.

The cause of unintended childlessness can lie with either the man or the woman.

The semen analysis provides information about possible male infertility. The affected couple may then, if necessary, consider methods of assisted reproduction, such as

• insemination or
• in vitro fertilization

.

Pregnancy is often still possible through assisted reproduction © koya979 | AdobeStock

A semen analysis can also be used to verify the success of a vasectomy (sterilization). This provides the man with absolute certainty regarding his permanent infertility and, thus, the success of the procedure.

Sperm analyses are typically performed by reproductive medicine specialists and/or andrologists.

To ensure an accurate semen analysis, the man must abstain from ejaculation for three days. He then provides a semen sample through masturbation. This abstinence period prevents any compromise in sample quality that could result from abstaining for too short or too long a period. This ensures that the results are comparable.

The ejaculate is collected under aseptic conditions into a sterile container. The patient can provide the semen sample on-site at the specialist’s office in designated rooms. If he finds this uncomfortable, he can also do so at home in his familiar surroundings. However, the sample must then be delivered to the specialist quickly. It should not be older than 30–60 minutes when the semen analysis is performed.

This is followed by a macroscopic and microscopic examination. At the end of the examination, the semen quality is compared with the underlying WHO reference values. This allows for reliable conclusions regarding the patient’s fertility.

A semen analysis begins with a macroscopic examination. This examination of the seminal fluid is performed without the use of a microscope. Among other things, the following are examined:

• volume,
• odor,
• color,
• viscosity, and
• pH level

of the ejaculate.

This is followed by a more detailed examination under a microscope. During this microscopic examination, a small amount of the ejaculate is analyzed under standardized conditions using a microscope.

Among other things, the following are examined in detail: the

• total count,
• concentration, and
• motility

of the sperm.

Stained semen sample under a light microscope © Bobjgalindo - Own work, CC BY-SA 4.0, Link

Macroscopic analysis of seminal fluid

The following characteristics are examined during macroscopic analysis:

• Liquefaction time: Shortly after being expelled from the seminal ducts, the ejaculate is initially viscous. It liquefies again after half an hour. If this liquefaction does not occur, it is referred to as a hyperviscosity disorder.
• Volume: According to the WHO, the volume should be at least 1.5 ml per ejaculation. An insufficient volume of semen indicates a lack of seminal vesicle secretion. Seminal vesicle secretion normally accounts for about two-thirds of the seminal fluid. Blocked ducts from the seminal vesicles can be the cause of an insufficient ejaculate volume.
• Color: Healthy semen has a whitish, cloudy color. Discoloration can have various causes: A yellowish color indicates an infection. A reddish color indicates the presence of red blood cells (erythrocytes). A brownish color may indicate the presence of blood, for example.
• pH level: According to the WHO, the pH level of seminal fluid should be between 7.2 and 8. If the value is higher, this may be the result of an infection. Lower values may result from a malformation or blockage of the vas deferens, seminal vesicle, or epididymis.

Microscopic Analysis of Semen

As part of the microscopic examination,

• the total number of sperm per ejaculate,
• the sperm concentration per milliliter of ejaculate, as well as
• motility and viability are assessed.

In addition, the test determines

• how long it takes for the ejaculate to liquefy and
• what the external shape (morphology) of the spermatozoa looks like.

Infertility is ruled out if the semen meets the following normal values:

• The semen sample should have a total sperm count of 39 million.
• The sperm concentration should be 15 million per milliliter.
• Sperm motility should be at least 40 percent (total motility).
• 32 percent of the sperm should exhibit rapid forward movement (progressive motility).
• Sperm viability should be at least 58 percent.
• The time to liquefaction should be between 15 and 30 minutes.

All of the values listed are minimum values.

Sperm cells also typically have

• an oval head,
• a short midpiece, and
• a tail

. An abnormal sperm cell deviates from this standard in its external shape. For example, the head may be too small, and damage may be found in the midpiece and tail.

In general, the percentage of normally shaped sperm must not fall below four percent.

Furthermore, according to the WHO, the seminal fluid should contain fewer than one million leukocytes (white blood cells) per milliliter. Leukocytes in the ejaculate may result from inflammation of the vas deferens.

The results of the semen analysis are compared with the WHO reference values described above to determine fertility. Normal fertility, or the ability to conceive, requires that the quality of the patient’s semen meet these values. If this is the case, unrestricted fertility is guaranteed.

Infertility can have various causes:

• mumps,
• sexually transmitted diseases, or
• injuries to the genital area

may have caused inflammation of the seminal ducts or led to their blockage. Varicose veins in the testicles can cause the testicles to overheat, leading to permanent damage to the sperm.

Environmental factors such as

• smoking,
• excessive alcohol consumption, and
• stress

also have a negative impact on sperm quality.

If a value that deviates from the norm suggests infertility, this does not necessarily mean anything. After about two months, another semen analysis is performed. This can confirm or rule out any existing suspicion of reduced fertility.