What are the semen tests? Learn about the five test items early

Semen examination includes many items. The general examination includes semen volume, color and transparency, viscosity and liquefaction, acidity and alkalinity, etc. If under a microscope, the sperm survival rate, sperm motility, etc. can be checked.

General examination

1. Semen volume

Normal people have an ejaculation volume of about 2-6 ml each time, 1-2 ml is suspiciously abnormal, and less than 1 ml or more than 7 ml are considered abnormal. The measurement of semen volume is related to the abstinence period before the sample is collected. The longer the abstinence period, the more semen there is. Generally, 3-7 days of abstinence is appropriate.

2. Color and transparency

Normally, the semen just ejaculated is milky white or grayish white, and becomes translucent milky white after liquefaction. It may be light yellow if the semen has not been ejaculated for a long time. Bright red or dark red blood-sperm is seen in reproductive system inflammation, tuberculosis, and tumors, and yellow purulent semen is seen in seminal vesiculitis or prostatitis.

3. Viscosity and liquefaction

Normal fresh semen is viscous and jelly a few seconds after discharge, and begins to liquefy after 30 minutes under the action of fibrinolytic enzymes in the semen. If the viscosity decreases and becomes rice soup-like, it may be due to a decrease in the number of sperm, which is seen in reproductive system inflammation. If the semen does not coagulate, it is seen in seminal vesicle obstruction or damage. If the semen does not liquefy after 1 hour, it may be due to inflammation that destroys fibrinolytic enzymes, such as prostatitis. The failure of sperm liquefaction can inhibit sperm motility and affect conception.

4. Acidity and alkalinity

Normal semen is slightly alkaline with a pH of 7.2 to 8.0, which helps neutralize acidic vaginal secretions. A pH value less than 7 or greater than 8 can affect sperm activity and metabolism, which is not conducive to conception.

1. Sperm survival rate: 30 to 60 minutes after ejaculation, the normal sperm survival rate should be 80% to 90%. A decrease in sperm survival rate is an important cause of infertility.

2. Sperm motility

Refers to the activity state of sperm, and also refers to the quality of active sperm. The World Health Organization (WHO) recommends that sperm motility be divided into 4 levels: ① Sperm activity is good, moving quickly, vigorously, and moving forward in a straight line; ② Sperm activity is relatively good, the movement speed is fair, the swimming direction is uncertain, and the movement is straight or non-straight, with whirlpools; ③ Sperm movement is poor, movement is slow, spinning or shaking in place, and the ability to move forward is poor; ④ Dead sperm, sperm is completely inactive. Normal sperm motility should be above level ③. If >40% of sperm have poor activity (level ③, ④), it is often an important cause of male infertility. Low sperm motility is mainly seen in varicocele, non-specific infection of the urogenital system, and the use of certain drugs such as anti-malarial drugs and androgens.

3. Sperm count

The normal sperm count is 0.6×1012～1.5×0.012/L, which is equivalent to a total of 400×106～600×106 sperm discharged at one time. When the sperm count value is <20×106/ml or the total number of sperm discharged at one time is <100×106, it is a reduction in sperm, which exceeds the pregnancy limit and leads to infertility. Azoospermia is when no sperm is found in direct semen smear or centrifugal sedimentation. It is seen in congenital testicular dysplasia, malformation or acquired testicular damage and atrophy (such as testicular tuberculosis, inflammation, gonorrhea, endocrine diseases with abnormal pituitary or adrenal function, etc.), vas deferens obstruction or congenital vas deferens and seminal vesicle defects. It is an important cause of oligospermia or azoospermia, and also an important cause of infertility. Checking for sperm is also a way to check the effect of vasectomy. If there is no sperm in the semen after six weeks of vasectomy, it means the operation was successful. If there is still sperm in the semen after two months of vasectomy, it means the operation was unsuccessful.

4. Sperm morphology

Normal sperm has a flat oval head and a long, curved tail, similar to a tadpole; but some have pointed heads, large heads, or double heads, and short, bifurcated, or double tails. Abnormal sperm should be less than 10% to 15% in normal semen. If the number of abnormal sperm in semen is >20%, it will lead to infertility. It may be due to varicocele, toxic metabolites in the blood, lead pollution, or the use of large doses of radiation and cytotoxic drugs. If >1% of pathological immature cells are found in semen, including spermatogonia, spermatocytes and incompletely developed spermatids, it indicates that the spermatogenic function of the seminiferous tubules of the testis is affected or damaged by drugs or other factors. If sperm aggregation is >10%, it indicates reproductive tract infection or abnormal immune function.

5. Inflammatory cells

Normal semen contains less than one "+" number of white blood cells. Leukocytosis indicates infection in the reproductive tract or accessory glands.