Weak spermatozoa is a condition in which less than 50% of sperm with forward motion (class a and b) or less than 25% of sperm with class a motion in semen parameters, also known as low sperm motility. Only sperm with normal forward motion can ensure that the sperm reaches the abdomen of the fallopian tube and unites with the egg to form a fertilized egg.
If some factor affects the motility of the sperm, especially the forward motion, this will prevent the sperm from swimming to the egg at the optimal time and fertilization will not occur. In addition, if the sperm spend too much time in the vagina, the acidic environment will reduce the survival time of the sperm.
Causes
There are many causes of low sperm motility. They are summarized in the following categories.
1.Infection
Acute and chronic inflammation of the reproductive tract or reproductive glands such as the epididymis, vas deferens, seminal vesicles and prostate can reduce the motility of sperm. The effect of infection on sperm motility can be multifaceted. The direct effect of microorganisms on sperm, such as mycoplasma, can attach to the head, mid-section and tail of sperm, causing increased hydrodynamic resistance and slower movement when sperm make forward motion, affecting sperm viability and the ability to penetrate egg cells.
In addition, mycoplasma can cause partial sperm membrane defects or even membrane structure destruction, affecting the fertilization ability of sperm. E. coli can reduce sperm viability by binding to sperm through its own receptors; the indirect effect of microorganisms on sperm can be through the production or release of toxic substances, and mycoplasma produces NH3 during growth to have a direct toxic effect on sperm. Escherichia coli can produce sperm braking factor.
Decreased sperm viability due to infection can also be achieved by changing the pH of seminal plasma, which decreases significantly when the pH is below 7 or above 9. In patients with acute adnexal inflammation or epididymitis, the pH is more alkaline, while chronic adnexal inflammation can cause the pH to fall below 7. In addition, inflammation-induced leukocytosis in semen can lead to a decrease in sperm motility through direct and indirect causes. The lack of sperm motility caused by prostatitis may be the result of a combination of factors, which may be related to zinc disorders in addition to microorganisms, leukocytes, pH, etc.
2, abnormal semen liquefaction
The non-liquefaction or high viscosity of semen is one of the causes of male infertility, and one of the very important factors may be the infertility by affecting the motility of sperm. In seminal plasma with non-liquefied semen, elongated fibrin may be seen and intermeshed to reduce the space for sperm movement, and sperm are held back, while coarse fibers are seen connected by many fine fibers in a network, which may be responsible for mechanically limiting forward movement of sperm. The authors of this paper have used urokinase-type fibrinogen activator (uPA) alone on specimens of non-liquefied semen in vitro and found that when semen changed from non-liquefied to liquefied state, sperm viability and forward motility increased significantly, and the same effect was obtained with chymotrypsin.
3. Immunological factors
Anti-sperm antibodies (AsAb) can affect the fertilization function of sperm in several different ways. The effect on sperm viability may be that AsA b b binds to the tail of the sperm, which impedes sperm viability, reduces motility, and has poor penetration ability, as has been demonstrated by the markedly reduced ability to penetrate cervical mucus when anti-sperm antibodies are present against the tail of the sperm. Some scholars used AsAb positive serum and human sperm contact and observed a so-called sperm “shaking phenomenon” (shaking phenomenon), mainly the head and the entire tail of sperm combined with anti-sperm antibodies, the forward motion of sperm was inhibited, but the survival rate did not change significantly.
4.Endocrine factors
In addition to the role of endocrine hormones on spermatogenesis and maturation, they also affect sperm motility. gonzales et al. found that prolactin in seminal plasma has a linear relationship with sperm activity, it improves sperm oxygen uptake or affects sperm motility through the cAMP system, and reduces sperm motility when serum E2 levels are elevated. Excessive testosterone in seminal plasma may inhibit sperm motility.
5. Kartagener’s syndrome
Kartagener’s syndrome was first identified by Kartagener in the early 1930s and later confirmed by other scholars to be a congenital lack of ciliary structures, manifested by the inability of the cilia of each ciliated cell in the body to move, mainly the absence of ciliary dynein alms of peripheral microtubules. Patients with this syndrome may have chronic respiratory infections traced from their medical history, in addition to the inability of sperm to move.
6. Chromosomal abnormalities
Autosomal and sex chromosome abnormalities affect sperm viability and forward motility, in addition to sperm count. The ultrastructural apparatus known to be associated with sperm motility can have abnormal sperm tail structure due to genetic factors, for example, lack of inner or outer branching arms or absence of both arms. There can also be a lack of central junctions and central complex structures, as the interaction between the central microtubules and the radial spokes can mediate the gliding of the outer microtubules, and when this structure is abnormal, sperm motility can be impaired.
7, Varicocele
Varicocele can cause male infertility in several ways, not only by affecting spermatogenesis, but also by causing a decrease in sperm motility. The mechanism may be due to blood stagnation in the varicose veins, impaired microcirculation, lack of nutrient supply and reduced partial pressure of oxygen, insufficient energy production and endocrine dysfunction. In addition, varicocele may also cause a decrease in sperm viability indirectly due to autoimmunity such as the production of anti-sperm antibodies and mycoplasma infection.
8.Other factors
(1) trace elements in seminal plasma zinc, copper, magnesium and semen quality, seminal plasma zinc content is more than 100 times the plasma content, low sperm vitality patients in the seminal plasma of zinc, iron, magnesium content is significantly lower than the normal vitality of healthy men. Zinc delays lipid oxidation of cell membranes and maintains the stability and permeability of cell structure, thus ensuring good sperm motility. The high content of the trace element cadmium (Cd) can lead to reduced sperm motility, cadmium can directly inhibit the oxidative enzymes of sperm and directly inhibit the motility organs of sperm, and the cadmium content in the semen of infertile men is significantly higher than that of fertile men.
(2) Lack of enzymes or reduced enzyme activity related to sperm motility, vitamin deficiency, engagement in high temperature, radiation occupations and exposure to chemical toxins can all cause reduced sperm motility.
(3) Smoking, alcohol consumption and drug factors Nicotine in tobacco affects sperm vitality through direct and indirect damage to sperm, long-term alcoholics can directly and indirectly affect sperm motility, and there are more drugs that affect sperm vitality.
There are also some people with low sperm motility whose cause cannot be detected, called idiopathic weak spermatozoa.
Prevention methods.
1, try not to use or less use of various chemicals, from the dry cleaners to get back the clothes best put a few days before wearing, because dry cleaning agents can affect the male sexual function; go to bed before 11 o’clock every day, sweat every day, try to eat unprocessed pure natural food.
2, prevent various infectious diseases that endanger male fertility, such as mumps, sexually transmitted diseases.
3, found that the testicles have different changes from the usual, such as swelling, hardening, bumpy, pain, etc., must be timely diagnosis and treatment.
4.Avoid excessive noise. According to the data, it is proved that men live in the environment of 70-80 decibels of noise for a long time, sexual function tends to be weakened, living in the high noise environment of 90 decibels or more sexual function disorders.
5, avoid long masturbation. It will trigger slow congestion of the prostate gland, leading to sterile prostatitis, affecting semen nutrients, quantity, viscosity, acidity and induce infertility.
6, do not eat too greasy food, quit smoking and alcohol. The germ cells in the testicles are affected by the harmful components of tobacco, making the quantity and quality of sperm poor, more sterile or to deformed children. Excessive alcohol abuse can lead to chronic alcoholism, sperm stunting or loss of motility.