Among the five major causes of male weak sperm, this one ranks first!

The most important part of a man's semen is the sperm, and in medicine, the sperm has a certain ability to move. The reason why the fertilized egg can be formed in the female body is that the sperm breaks through many obstacles and combines with the egg. However, if a man suffers from asthenospermia, the sperm may not have such ability. So, what is the cause of asthenospermia in men?

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 impact of infection on sperm motility can be multifaceted. The direct effect of microorganisms on sperm, such as mycoplasma can be adsorbed on the head, middle and tail of sperm, so that when the sperm moves forward, the hydrodynamic resistance increases and the movement speed slows down, affecting the sperm motility and the ability to penetrate the egg cell. In addition, mycoplasma can cause partial sperm membrane defects or even membrane structure damage, affecting the fertilization ability of sperm. Escherichia coli can reduce sperm motility 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. Mycoplasma produces NH3 during the growth process, which has a direct toxic effect on sperm. Escherichia coli can produce sperm inhibitory factors. Infection can also cause a decrease in sperm motility by changing the pH value of semen. When the pH value is lower than 7 or higher than 9, sperm motility decreases significantly. In patients with acute epididymitis or epididymitis, the pH value is mostly alkaline, while chronic epididymitis can cause the pH value to be lower than 7. In addition, the increase in leukocytes in semen caused by inflammation can lead to a decrease in sperm motility through direct and indirect reasons. The lack of sperm motility caused by prostatitis may be the result of a combination of factors. In addition to factors such as microorganisms, leukocytes, and pH value, it may also be related to zinc disorders.

2. Abnormal semen liquefaction

Semen that does not liquefy or has high viscosity is one of the causes of male infertility, and one very important factor may be that it affects the motility of sperm, leading to infertility. In the seminal plasma of semen that does not liquefy, thin and long fibrils can be seen, which are intertwined with each other, reducing the space for sperm movement and restraining sperm. At the same time, thick fibers are also seen to be connected into a network by many thin fibers, which may be the reason for the mechanical restriction of sperm forward movement. The author of this article has used urokinase-type fibroblast activator (uPA) alone in vitro on semen samples that do not liquefy and found that when semen changes from a non-liquefied state to a liquefied state, sperm motility and forward motility are significantly improved, and the same effect is obtained using chymotrypsin.

3. Immune factors

Antisperm antibodies (AsAb) can affect the fertilization function of sperm in several different ways. The effect on sperm motility may be that AsAb binds to the tail of the sperm, which hinders sperm motility, reduces motility, and has poor penetration ability. This has been confirmed by the fact that when antisperm antibodies are present in 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 "shaking phenomenon" of sperm. It is mainly that the head and the entire tail of the sperm are bound to antisperm 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 is linearly related to sperm activity. It increases sperm oxygen uptake or affects sperm motility through the cAMP system. When the E2 level in serum increases, sperm motility is reduced. Excessive testosterone in seminal plasma may inhibit sperm motility.

5. Syndrome

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