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 sperm spend too much time in the vagina, the acidic environment will reduce the survival time of the sperm. According to the literature, about 30% of male infertility is caused by low sperm motility. Yan Liang, Department of Urology, First Affiliated Hospital of Zhengzhou University
The diagnosis of weak spermatozoa is made mainly based on routine semen analysis and medical history questioning. Abstinence is required for 3-7
The diagnosis of weak spermatozoa can be made after 3 to 7 d of abstinence and masturbation, after more than 3 consecutive semen routine analyses suggesting less than 50% of sperm forward motion (a+b level) or less than 25% of fast linear forward motion, sperm density greater than 20~106/mL, and other parameters normal or basically normal. or 1 h after ejaculation
h after ejaculation, sperm viability less than 50%, laboratory or other auxiliary examinations can find reproductive tract infection, or other diseases affecting sperm viability, can be diagnosed as weak spermatozoa.
So what are the causes of weak spermatozoa? There are many causes of low sperm viability, which 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, varicose veins of spermatozoa
Varicocele can lead to male infertility through a variety of ways; it not only affects the occurrence of sperm, but also causes a decrease in sperm viability. 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 autoimmunity such as the production of anti-sperm antibodies and mycoplasma infection indirectly causing the decrease of sperm vitality.
3.Abnormal semen liquefaction
Semen liquefaction or high viscosity is one of the causes of male infertility, and a very important factor may cause infertility by affecting the motility of spermatozoa. In seminal fluid that is not liquefied, thin fibrous proteins can be seen in the seminal plasma and mesh with each other so that the space for sperm activity is reduced and sperm are held back, while coarse fibers are also seen to be connected into a network by many fine fibers, which may be the cause of mechanical restriction of forward motion of sperm.
4.Immune factors
Anti-sperm antibodies (AsAb) can affect the fertilization function of sperm in several different ways. The effect on sperm viability may be that AsAb binds to the tail of the sperm, and sperm viability is hampered with reduced motility and poor penetration ability, which has been confirmed by the significantly reduced ability to penetrate cervical mucus when anti-sperm antibodies are present against the tail of the sperm.
5. Endocrine factors
In addition to the role of endocrine hormones on the occurrence and maturation of spermatozoa, they also affect the motility of spermatozoa.
6.Kartagener’s syndrome
In the early 1930s, Kartagener’s first discovered a condition that manifests as the inability of the cilia of each ciliated cell in the body to move, mainly because of the absence of the cilia-powered protein arm of the peripheral microtubules. Patients with this syndrome may have chronic respiratory infections traced from their medical history in addition to the inability to move sperm.
7. Chromosomal abnormalities
Autosomal and sex chromosome aberrations affect sperm viability and forward motility, in addition to sperm count. Ultrastructural devices known to be related to sperm motility can have abnormal sperm tail structure due to genetic factors.
8. Other factors
(1) trace elements zinc, copper and magnesium in seminal plasma are related to semen quality, seminal plasma zinc content is more than 100 times the plasma content, and the content of zinc, iron and magnesium in seminal plasma of patients with low sperm motility is significantly lower than that of healthy men with normal motility. Zinc delays lipid oxidation of cell membranes and maintains the stability and permeability of cell structures, thus ensuring good sperm motility.
(2) Lack of or reduced enzyme activity of enzymes 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 motility through direct and indirect damage to sperm, long-term alcoholics can directly and indirectly affect sperm motility, and there are many drugs that affect sperm motility, so please visit the clinic for specific consultation.