Post Date April, 15 2023
According to the World Health Organization (WHO), if a couple cohabits for more than 1 year and does not use any contraceptive measures, and the female partner becomes infertile due to male factors, it is called male infertility. Male infertility is not an independent disease, but a result of one or many diseases and factors.
1、 The causes of male infertility
1. Endocrine abnormalities
2. Genetic factors
3. Immune factors
4. Sexual dysfunction
5. Varicocele
6. Abnormal seminal tract
7. Congenital dysplasia of reproductive organs
8. Systemic chronic diseases and nutritional disorders
9. Environmental factors
10. Bad lifestyle habits
1. Endocrine diseases
Hypothalamic dysfunction, such as Kallmann syndrome, is mainly due to a lack of gonadotropin releasing hormone; Pituitary dysfunction, such as selective luteinizing hormone (LH) deficiency and FSH deficiency, hyperprolactinemia, etc. Adrenal cortical hyperplasia can inhibit the secretion of FSH and LH by the pituitary gland, leading to infertility.
2. Genetic factors
The main chromosomal abnormalities are male pseudohermaphroditism, Klinefelter syndrome, and XYY syndrome. Chromosome abnormalities such as 46XY/47XXY can cause testicular spermatogenesis disorders.
3. Immune factors
Both male and female antisperm antibodies can affect sperm motility and egg penetration.
4. Sexual dysfunction
Erectile dysfunction, premature ejaculation, impotence, non ejaculation and retrograde ejaculation can all cause male infertility.
5. Varicocele
Varicocele refers to the obstruction of venous return, valve failure, and blood reflux in the spermatic cord, causing blood stasis, leading to the expansion, elongation, and bending of the racemose venous plexus. Most people believe that varicocele can affect sperm development and semen quality, leading to infertility.
6. Abnormal seminal tract
Abnormalities in the pipeline for transporting sperm, such as obstruction of the seminal tract, can prevent sperm from being transported well and cannot bind to the egg, leading to infertility.
7. Congenital dysplasia of reproductive organs
It can cause difficulty for the penis to enter the vagina, prevent semen from ejaculating into the vagina normally, and lead to infertility. Common causes include penile defects, small penises, large penises, and severe hypospadias. In addition, the dysplasia of the testis will lead to spermatogenesis obstacles, which will lead to infertility.
8. Systemic chronic diseases and nutritional disorders
Chronic disease does not specifically refer to a certain disease, but rather a general term for a type of disease that has a hidden onset, a long course, and a persistent condition, lacks accurate evidence of infectious biological causes, a complex etiology, and some diseases that have not yet been fully confirmed. It is a kind of disease caused by excessive or insufficient nutrients in the body, or imbalance that causes overnutrition or nutrition deficiency in the body, and abnormal nutrition metabolism.
9. Environmental factors
The main environmental reasons for male infertility are high temperature, metal environment, radioactive environment, etc.
10. Bad lifestyle habits
Long term wearing of tight pants, smoking and alcohol abuse, exposure to toxic substances, frequent hot baths, improper or excessive sexual activity, frequent long-distance and overworked cycling, and radiation damage.
2、 Diagnostic classification of male infertility
1. According to semen classification:
According to the WHO "Laboratory Manual for Human Semen Examination and Processing" (5th edition), the reference values for semen examination are as follows:
(1) Immunological infertility
(2) Abnormal sperm disease
(3) Asthenozoospermia
(4) Oligospermia
(5) Azoospermia
(6) Azoospermia
2. Classification based on diseases and factors that interfere or affect the reproductive environment:
It is divided into three stages: pre testicular, testicular, and post testicular.
3、 Physical examination
（1） Medical history collection
1. Past history
2. Professional and personal habits
3. History of marriage, sexual activity, and childbirth
4. Family history
（2） Physical examination
1. General inspection
2. Reproductive organ examination
(1) Testis (2) Epididymis
(3) Penis (4) scrotum
(5) Vas deferens (6) spermatic vein
(7) Digital examination of the rectum in the inguinal region (8)
The reproductive organs are the focus of examination for male infertility patients. The main task is to carefully examine the penis, scrotum, prostate, and seminal vesicle in sequence. Attention should be paid to the size, position, shape, foreskin, and urethral opening of the penis. Sick penile size, inverted position of the penis and scrotum, severe curvature of the penis, phimosis, and movement of the urethral opening (hypospadias) can all affect fertility.
4、 Routine semen examination
（1） General trait inspection
（2） Microscopic examination
1. Sperm survival rate 2. Sperm motility
3. Sperm morphology analysis 4. Semen white blood cell examination
5. Sperm acrosome reaction
Routine semen examination includes general examination and microscopic examination.
（1） General trait inspection
1. Semen volume
The amount of ejaculation per ejaculation in a normal person is approximately 2-6 milliliters, with 1-2 milliliters being a suspected abnormality. Any ejaculation less than 1 milliliter or greater than 7 milliliters is considered abnormal.
2. Color and Transparency
Normal ejaculated semen appears milky white or gray white, and after liquefaction, it appears semi transparent milky white. Those who have not ejaculated for a long time may appear light yellow. Bright red or dark red semen is found in reproductive system inflammation, tuberculosis, and tumors, while yellow pus like semen is found in seminal vesiculitis or prostatitis.
3. Viscosity and liquefaction
Normal fresh semen is in the form of thick jelly a few seconds after being discharged, and begins to liquefy 30 minutes later under the action of plasmin in semen. If the viscosity decreases in a rice soup like manner, it may be due to a decrease in sperm count, as seen in inflammation of the reproductive system, and non coagulation of semen, as seen in obstruction or damage to the seminal vesicles; If semen does not liquefy after 1 hour, it may be caused by inflammation that destroys plasmin, such as prostatitis. If sperm does not liquefy, it can inhibit sperm activity and affect pregnancy.
4. PH
Normal semen is weakly alkaline with a pH of 7.2 to 8.0, which is beneficial for neutralizing acidic vaginal secretions. pH values below 7 or above 8 can affect sperm activity and metabolism, which is not conducive to conception.
（2） Microscopic examination
1. Sperm survival rate
After 30 to 60 minutes of ejaculation, the normal sperm survival rate should be 80% to 90%, and a decrease in sperm survival rate is an important cause of infertility.
2. Sperm motility
Refers to the state of sperm activity and also refers to the quality of active sperm. The World Health Organization (WHO) recommends dividing sperm motility into four levels: ① good sperm motility, rapid movement, lively and powerful, and straight forward movement; ② Sperm activity is good, the movement speed is moderate, the swimming direction is uncertain, and it moves in a straight or non straight line with convolution; ③ Sperm motility is poor, slow to move, rotates or shakes in place, and has poor ability to move forward; ④ Dead sperm, completely inactive sperm. Normal sperm motility should be above level ③. If>40% of sperm motility is poor (level ③, ④), it is often an important cause of male infertility.
3. Sperm morphology analysis
Normal sperm have a flat oval head and a long and curved tail, similar to a tadpole; But some of the heads are pointed, large, or double headed, and the body and tail are thick, short, forked, or double tailed. In normal semen, abnormal sperm morphology should be less than 10% to 15%. If the number of abnormal sperm morphology in semen is greater than 20%, it will lead to infertility. If more than 1% of pathological immature cells are found in semen, including spermatogonium, spermatocyte and underdeveloped spermatid, it indicates that the spermatogenic function of seminiferous tubules of testis is affected or damaged by drugs or other factors. If sperm agglutination exceeds 10%, it indicates reproductive tract infection or abnormal immune function.
4. Semen white blood cell test
Generally, a routine semen examination shows a normal white blood cell count of 6 to 10, with less than one "+" sign in normal semen. An increase in white blood cells indicates an infection in the reproductive tract or accessory gonads.
5. Sperm acrosome reaction
It refers to a series of changes that occur in the acrosome after Capacitation meets the egg in the ampulla of the fallopian tube; Specifically, it is the process of sperm releasing acrosin, which dissolves the corona radiata and zona pellucida. Acrosome reaction is an important physiological process occurring after Capacitation, and is a prerequisite for fertilization. Only sperm that have completed the acrosome reaction can fuse with oocytes and achieve fertilization.
