What causes asthenospermia and symptomatic treatment

The motility or movement ability of sperm is directly related to human reproduction, so there is a saying about ensuring "high quality" sperm. Only sperm that move forward normally can ensure that they reach the ampulla of the fallopian tube and combine with the egg to form a fertilized egg. So what is the cause of asthenospermia?

1. Infect

Acute and chronic inflammation of the reproductive tract or reproductive glands such as the epididymis, vas deferens, seminal vesicles and prostate can reduce sperm motility. The effects of infection on sperm motility can be multifaceted. Direct effects of microorganisms on sperm, such as mycoplasma can adsorb on the head, middle part and tail of sperm, increasing the fluid dynamic resistance and slowing down the movement speed when the sperm moves forward, affecting the sperm motility and ability to penetrate the egg cell. In addition, mycoplasma can cause partial sperm membrane defects or even membrane structure destruction, affecting the sperm's fertilization ability. Escherichia coli can reduce sperm motility by combining with sperm through its own receptors; microorganisms can indirectly affect sperm by producing or releasing toxic substances. Mycoplasma produces NH3 during its growth process, which has a direct toxic effect on sperm. Escherichia coli can produce sperm braking factor. Infection can also cause a decrease in sperm motility by changing the pH value of seminal plasma. When the pH value is lower than 7 or higher than 9, sperm motility decreases significantly. Patients with acute accessory gland inflammation or epididymal inflammation tend to have an alkaline pH, while chronic accessory gland inflammation may 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. In addition to factors such as microorganisms, white blood cells, and pH values, it may also be related to zinc disorders.

2. Abnormal semen liquefaction

Semen failure to liquefy or high viscosity is one of the causes of male infertility, and an important factor may be causing infertility by affecting sperm motility. In the seminal plasma of non-liquefied semen, long and thin fibrins can be seen, which are entangled with each other, reducing the space for sperm movement and restraining the sperm. At the same time, coarse fibers are connected into a network by many fine fibers. These may be the reasons for the mechanical restriction of the forward movement of sperm. The authors of this article have used urokinase-type plasminogen activator (uPA) alone in vitro on non-liquefied semen samples and found that when the semen changes from a non-liquefied state to a liquefied state, the sperm motility and forward motility are significantly improved. The same effect was obtained using chymotrypsin.

3. Immune factors

Antisperm antibodies (AsAb) can affect the fertilizing function of sperm in several different ways. The effect on sperm motility may be that AsA b binds to the sperm tail, which hinders sperm motility, reduces motility, and poorly penetrates the sperm. This has been confirmed by the fact that when anti-sperm antibodies are present on the sperm tail, the ability to penetrate cervical mucus is significantly reduced. Some scholars have used AsAb positive serum to contact human sperm and observed a so-called sperm "shaking phenomenon". It is mainly that the head and the entire tail of the sperm are combined with anti-sperm antibodies, and the forward movement of the sperm is inhibited, but the survival rate does not change significantly.

4. Endocrine factors

In addition to affecting the occurrence and maturation of sperm, endocrine hormones also affect the motility of sperm. Gonzales et al. found that prolactin in seminal plasma was linearly related to sperm activity. It increased sperm oxygen uptake or affected sperm motility through the cAMP system. When the E2 level in serum increased, sperm motility was reduced. Excessive levels of testosterone in seminal plasma may inhibit sperm motility.

5. Syndrome

In the early 1930s, Karolinska Institutet first discovered a disease that was later confirmed by other scholars to be a congenital lack of ciliary structure, manifested by the inability of cilia of ciliated cells in the body to move, mainly due to the lack of dynein arms (dynein alms) of the peripheral microtubules. In addition to sperm motility, patients with this syndrome may also have chronic respiratory infections in their medical history.

6. Chromosomal abnormalities

In addition to affecting the number of sperm, autosomal and sex chromosome abnormalities also affect the motility and forward motility of sperm. The ultrastructural apparatus known to be involved in sperm motility can result in abnormalities in the sperm tail structure due to genetic factors, such as the lack of an inner arm, an outer arm, or both arms. It may also be due to the lack of central connection and central complex structure, because the interaction between the central microtubules and the radial spokes can regulate the sliding of the outer microtubules. When this structure is abnormal, sperm will have motility disorders.

7. Varicocele

Varicocele can cause male infertility in a variety of ways. It not only affects spermatogenesis, but also causes a decrease in sperm motility. The mechanism may be due to blood retention in varicose veins, microcirculatory disorders, lack of nutrient supply and decreased oxygen partial pressure, insufficient energy generation and endocrine dysfunction. In addition, varicocele may also lead to autoimmunity such as the production of antisperm antibodies and mycoplasma infection, which indirectly causes a decrease in sperm motility.

8. Other factors

(1) Trace elements such as zinc, copper, and magnesium in seminal plasma are related to semen quality. The zinc content in seminal plasma is more than 100 times that in plasma. The zinc, iron, and magnesium contents in the seminal plasma of patients with low sperm motility are significantly lower than those in healthy men with normal sperm motility. Zinc can delay lipid oxidation in cell membranes, maintain the stability and permeability of cell structure, and thus ensure good sperm motility. When the content of trace element cadmium (Cd) is high, it can lead to reduced sperm motility. Cadmium can directly inhibit sperm oxidase and sperm motility organs. The cadmium content in the semen of infertile men is significantly higher than that of fertile men.

(2) Lack of enzymes related to sperm motility or reduced enzyme activity, vitamin deficiency, exposure to high temperatures or radiation, and exposure to chemical toxins can all cause reduced sperm motility.

(3) Smoking, drinking and drug factors Nicotine in tobacco affects sperm motility by directly and indirectly damaging sperm. Long-term alcoholics can directly and indirectly affect sperm motility. There are many drugs that affect sperm motility.

There are also some people with low sperm motility for which the cause cannot be identified, which is called idiopathic asthenozoospermia.