What Is Semen Analysis?

Semen refers to the fluid that is ejected from the urethra by male animals or human males during ejaculation (usually in orgasm). Normal semen is a thick liquid mixture composed of sperm and seminal plasma, which accounts for more than 90% of the volume of seminal fluid. Sperm are produced by the testes, mature within the epididymis, and are output through the insemination tube. The seminal plasma is mainly a mixed fluid secreted by the accessory glands such as the prostate, seminal vesicle glands, and urethral glands, as well as a small amount of testicular fluid and epididymal fluid. In addition to a large amount of water, fructose, proteins and peptides, seminal plasma also contains a variety of other sugars (such as glucose), enzymes (such as prostaglandins), inorganic salts and small organic molecules, which can provide nutrients and energy for sperm. In normal times, the sperm and seminal plasma components "settle in place". During the process of ejaculation, sperm and seminal plasma are mixed to form semen.

Basic Information

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Andrology, Urology

Factors affecting semen

Due to the deterioration of global environmental conditions and lifestyle changes, the semen quality has decreased significantly, leading to an increase in the incidence of infertility. Many scholars have conducted extensive research on the factors affecting sperm treatment and found that environmental pollution is the main cause of sperm quality decline, and secondly it is related to lifestyle.

Physical factor

(1) Influence of temperature factors Sperm production and growth require a relatively low temperature of 35 ° C. High temperature and cold environments will seriously affect its health quality.

(2) Effects of electromagnetic radiation Testicles are one of the most sensitive tissues and organs in the human body. Excessive use of mobile phones can reduce sperm count, vitality, and increase sperm abnormalities. Microwaves can damage spermatogenic cells through thermal effects, affect the endocrine function of the testes, cause an increase in the rate of sperm deformity, and reduce quality.

(3) The effects of high-frequency vibrations. Continuous and severe vibrations can cause abnormalities in autonomic nerve function, immune function, hemorheology, and endocrine function of endothelial cells. These abnormalities may affect reproductive function and directly lead to sperm maturation disorders Wait.

2. The influence of chemical factors

Chemical factors mainly come from environmental pollution. Environmental pollution is the main way to harm male reproductive function, because male reproductive system is highly sensitive to environmental pollution.

3. Impact of lifestyle

For example, wearing tight underwear, excessively high bath water temperature, excessively long cycling time, long-term driving, sedentary movement, strenuous exercise, smoking, heavy drinking, excessive intake of saturated fat, etc. will all have an adverse effect on sperm.

4. Influence of infection factors

Some studies have found that the quality of men's semen changes significantly after genital tract infections, such as reproductive tract inflammation, tuberculosis, etc. can lead to reduced semen, reduced sperm density, vitality, and insemination ability. In patients with herpes simplex virus (HSV) infection, sperm quality examination will reduce sperm motility and survival rate, and semen quality will improve with the degree of virus control. Ureaplasma urealyticum (UU) infected patients may have abnormal semen quality.

5. The effect of trace elements

The seminal plasma contains high concentrations of zinc. Zinc deficiency causes sexual dysfunction, decreased sperm density, decreased testosterone synthesis, amino acid metabolism disorders, protein synthesis disorders, and sperm formation stagnation. Zinc deficiency can affect seminal plasma metabolism and sperm activity.

6. Disease factors

About 40% of infertile men have varicocele of varying severity. Varicocele can affect testicular blood supply and the production of healthy semen.

7. Drug factors

Certain drugs can also affect semen treatment and cause male infertility such as the chemical drugs cyclophosphamide, methotrexate, colchicine; antihypertensive drugs spironolactone, guanethidine, propranolol, reserpine; macrocyclic Lactone antibiotics erythromycin, spiramycin, medicillin; hormone hydrocortisone; sedatives phenobarbital, diazepam, clozazem; drugs cannabis, heroin; Chinese medicine tripterygium wilfordii, horse chestnut , Sophora flavescens, Pig bile, Shan Cigu, Tu Fritillaria, Gypsophila, Soapweed, etc.

Standard of normal semen

Normal semen is one of the most basic conditions for achieving fertility. The analysis of semen quality cannot be concluded from only one index of semen, and comprehensive analysis of multiple indicators should be performed. Commonly used indicators to evaluate semen quality include:

Semen volume

Refers to the volume of semen ejected from one ejaculation, which is inversely related to the frequency of ejaculation. The normal amount should be more than or equal to 1.5 to 2 ml (ml). If the amount of ejaculation is more than 8ml, it is too much. If the total amount is less than 1.5 (5 to 7 days of abstinence), the amount of semen is small. Too much or too little semen can easily lead to infertility.

2. Color

The color of normal semen is off-white or slightly yellow, and it is translucent milky white after liquefaction. Those who have not ejaculated for a long time may be slightly yellow. If the semen is yellowish green, there may be inflammation in the male reproductive tract or paragonads (such as prostatitis and seminal vesicles). If the semen is red (including bright red, light red, dark red, or soy sauce), it is highly suspected that the semen contains blood (hematospermia). Those who have a large number of red blood cells can be diagnosed as blood sperm, which is common in paragonads and posterior urethral inflammation Patients, occasionally seen in patients with tuberculosis or tumors.

3. Odor

The scent of semen is produced by prostate fluid, and it usually has a fishy smell. When the prostate's secretory function is impaired, semen will lack this fishy smell.

4.Liquefaction time

When the semen is discharged from the body, it is in a gel state and becomes liquid after a period of time. This process is called liquefaction. The liquefaction time is the time required for the newly discharged semen to change from a gel to a free-flowing state. At room temperature, normal semen samples are completely liquefied within 60 minutes. If the semen is not liquefied after 30 minutes, it is abnormal.

5. Viscosity

The liquefied semen is touched with a glass rod, and the semen filaments are formed after being gently lifted. If the semen is normal, the length of the semen filaments should be less than 2 cm, otherwise it is considered abnormal.

6. pH (PH value)

The semen was weakly alkaline with a pH of 7.2 to 7.8.

7. refined berry sugar concentration

Fructose in semen is the energy source of sperm activity. The concentration of refined berry sugar is generally between 9.11 and 17.67 mmol / L.

8. Zinc content in semen

The concentration of zinc in seminal plasma is more than 100 times higher than that in plasma. It plays an important role in promoting the development of reproductive organs, maintaining normal spermatogenesis, and protecting the prostate. Under normal circumstances, the zinc content in a ejaculate should be greater than 2.4 mol.

9. Sperm concentration

The normal sperm count should exceed 15 million / ml or the total number of sperm discharged from one ejaculation is 39 × 10.

10. Sperm motility

According to the new WHO experiment manual, sperm are simply divided into PR type (progressive (forward motion)), NP (non-progressive, non-progressive) type, and IM (non-progressive) type, regardless of the sperm motility function. immotility, completely immobile) type. The normal reference values are PR 32% and PR + NP 40%.

11. Sperm survival rate

Refers to the proportion of live sperm in a drop of semen. The lower limit of the reference value is 58%.

12. Sperm morphology

Malformed sperm are abnormally shaped sperm that may affect fertility.

In 2010, the World Health Organization launched a new "Human Semen and Sperm-Cervical Mucus Interaction Laboratory Test Manual" (fifth edition). According to this standard, semen is normal when the semen examination meets the following conditions. It should be noted that the sperm quality cannot be determined by only one semen examination. Those who fail the first inspection must review the semen once or twice within two to three weeks, and make a comprehensive analysis based on several results before making a judgment.

parameter	Reference low
Semen volume (ml)	1.5 (1.4-1.7)
Total sperm (10 / times)	39 (33-46)
Sperm density (10 / ml)	15 (12-16)
Total vitality (PR + NP,%)	40 (38-42)
Forward motion (PR,%)	32 (31-34)
Survival rate (surviving sperm,%)	58 (55-63)
Sperm morphology (normal morphology,%)	4 (3.0-4.0)
Other recognized reference values
pH	7.2
Peroxidase positive leukocytes (10 / ml)	<1.0
MAR test (mixed agglutination test,%)	<50
Immunobead test (wrapped motile sperm,%)	<50
Seminal plasma zinc (mol / time)	2.4
Refined berry sugar (mol / time)	13
Seminal plasma neutral glucosidase (mol / time)	20

Semen check

Semen tests are mainly used to assess male fertility, assist in the diagnosis of male reproductive system diseases, and provide high-quality sperm for artificial insemination and sperm bank screening.

1. Semen specimen collection methods and precautions

(1) Specimen collection time should be at least 2 days and no longer than 7 days. The number of days for each abstinence review should be as constant as possible. The so-called abstinence refers to the cessation of sexual life, and no masturbation, dreamlessness, etc. Abstinence time affects sperm density, but sperm motility is not affected by the length of abstinence time.

(2) Complete collection of semen During ejaculation, the front part is rich in sperm, and the back part is mainly composed of secretions from the seminal vesicle glands. Therefore, the loss of semen in the front part has a greater impact on the semen analysis results than the loss of the latter part. If there is any loss, the inspection is abolished, and it should be collected and retested after 2-7 days of abstinence.

(3) Precautions for collection Before collecting semen, smoking and alcohol should be banned, and drugs that have an effect on spermatogenesis should be avoided. Semen samples cannot be collected with a condom. It is not recommended to collect semen samples by interrupted sexual intercourse. The container holding the semen should be clean, sterile, and dry. The temperature of the container before the sperm should be the same as the room temperature; the bottle should not be too large, but the mouth of the bottle should not be too small to prevent the semen from being ejected out of the bottle; it should also be labeled. Record the name and retrieval time. In cold weather, semen specimens should be kept warm, placed in a lingerie bag, not tilted or inverted, and delivered to the laboratory within 1 hour if possible.

(4) Specimen collection method It is better to pick up the sperm in the morning. Wash your hands, genitals, especially the glans with warm water before picking. Can use masturbation method or electric massage ejaculation method to cause ejaculation. Because the semen is discharged in a certain order, the first part comes from the prostate, epididymis and ampulla, with a large number of sperm, and the last part comes from the seminal vesicle. Therefore, the entire semen should be collected, not to miss any part, especially the first part. Because the first part of semen is easily lost, semen cannot be collected by external ejaculation.

2. Inspection items

(1) General character inspection Including the determination of semen volume, color, viscosity, odor and liquefaction time.

(2) Microscopic examination includes inspection of sperm survival rate, sperm motility, sperm concentration, sperm morphology, and other non-sperm cells such as spermatogenic cells, red blood cells, and white blood cell counts.

(3) Chemical inspection Determine the pH value of semen; the content of fructose, zinc, carnitine, and citric acid in seminal plasma; the activities of acid phosphatase, lactate dehydrogenase, and acrosome enzyme in seminal plasma.

(4) Immunological examination Detects antisperm antibodies, immunosuppressants, immunoglobulins, etc. in seminal plasma.

(5) Microbiological examination Smear or culture of semen to check the microorganisms in the semen. Such as bacteria, mycoplasma, chlamydia, syphilis and viruses.

(6) Sperm function test is mainly to evaluate sperm penetration and motor vitality.

Method for improving semen quality by semen

1. Reduce the factors that damage the quality of semen

Including not wearing tight pants, stay away from sauna, hot water bath, sedentary, avoid heavy drinking, resolutely quit smoking, weight control within the standard range, drink less coffee, eat less fast food and so on.

2. Reasonable diet

From a nutritional perspective, sufficient amounts of protein, vitamins, and trace elements can promote sperm production. For example, vitamin A, vitamin B, and vitamin E can increase reproductive functions. In addition, some trace elements such as zinc, manganese, and selenium Deficiency also affects men's fertility.

3. Pay attention to environmental factors

Pay attention to protect against electromagnetic radiation: Put your mobile phone in your jacket pocket. When operating the computer, keep a distance of not less than 70 cm from the computer screen and a distance of not less than 120 cm from the back and sides of the computer. Do not put a laptop On your knees. Newly renovated houses are best left for a period of time. Although now known as "green decoration", there may still be some radiation and volatile substances in the furniture and paint.

4. Psychological adjustment

It is now generally in a tense pace of life, and the huge pressures it faces will also affect sperm quality. If the husband and wife blame each other because of family chores, both parties are in depression or trouble all day, which can directly affect the nervous system and endocrine function of the body, cause disorders in testicular spermatogenesis, and may cause infertility. It is necessary to adjust and maintain a good mentality, do things that can relax you, such as walking, bathing, playing games, etc., to face various pressures and problems with a positive, scientific method and healthy living behavior.

5. Save labor, avoid staying up late, moderate exercise

"Labour" here refers to overwork caused by various factors, including work, study, life and sports. Modern medical research shows that overwork can affect spermatogenesis and make sperm less active. Staying up late will also affect the secretion and quality of semen. Generally speaking, it is best to fall asleep around 10 o'clock in the evening, so the quality of sperm produced is better. Needless to say the benefits of exercise, but the intensity of exercise should be moderate, strenuous exercise, such as marathon and long-distance cycling will increase the temperature of the testes, destroying the cool environment needed for sperm growth.