The cause of male infertility may be environmental factors, such as:

• Industrial chemicals. Prolonged exposure to benzene, toluene, xylene, pesticides, herbicides, organic solvents, paintwork materials and lead has a negative impact on semen quality and quantity.
• Heavy metals. Exposure to lead or other heavy metals can also depress spermatogenesis.
• Radiation or X-rays. Exposure to radiation can significantly reduce the amount of sperm in your semen. As a rule, the effect is reversible and after a while the semen parameters are restored to normal values. At high radiation doses, semen production can be irreversibly impaired.
• Testicular overheating. An increase in the temperature of the scrotum has a negative effect on spermogenesis. Frequent use of saunas, baths can worsen the quality of semen. Prolonged sitting, tight underwear and clothing, and working with a laptop on your lap can also increase the temperature of the scrotum and adversely affect semen production.

Lifestyle, bad habits and working conditions also affect male fertility:

• Drug use. Cocaine and marijuana have a reversible negative effect on the quality and quantity of sperm.
• Excessive use of alcohol. Alcohol abuse can reduce testosterone levels, cause erectile dysfunction, and reduce sperm production. Liver diseases caused by excessive alcohol consumption also lead to fertility problems.
• Smoking tobacco. Men who smoke have significantly worse sperm quality than non-smokers. Passive smoking can also have an impact on male fertility.
• Emotional stress. Hormones produced during stress inhibit the secretion of substances that stimulate spermatogenesis. Prolonged and severe stress can lead to significant changes in sperm parameters.
• Excess weight. Obesity brings an imbalance in the normal male hormonal status, which leads to a decrease in male fertility.
• Occupational hazard. Men in some professions, such as drivers or welders, have a higher risk of infertility in relation to other men.

In 30% of men with sperm parameters violation it is not possible to determine the cause, this form of male infertility is called idiopathic (unreasonable).

Pathogenesis of male infertility

The process of creating spermatozoa (spermatogenesis) occurs in the testicle. 90-95% of the volume of testicles is represented by special tubes – seed tubules, in which the process of sperm creation – spermatogenesis takes place. The process of creating a single sperm takes about 70 days.

The process of spermatozoon creation is stimulated by follicle stimulating hormone (FSH), which is produced in the area of the brain – pituitary gland. In the absence of FSH, spermatogenesis does not occur, and spermatozoa is not formed.

Spermatogenesis is a delicate process. Many factors can disrupt its normal course (increase in scrotum temperature, taking medications, X-rays) and lead to the creation of sperm cells with an incorrect structure (morphology), poor mobility and defective genetic material, unable to fertilize.

After leaving the testicle, spermatozoa enters a long, curved tube called the appendage of the testicle. As a result of the passage of the appendage testis, which takes about a week, sperm improves its mobility, and there is a change in the molecules on the sperm surface, necessary for interaction with the egg.

Against the background of inflammatory processes in the epididymis of the egg, the process of maturation of sperm may be disturbed, and they will not be able to fertilize the egg. In some cases, as a result of an inflammatory process or after operations on the epididymis is formed an obstacle to the passage of sperm, as a result of which they do not get into the sperm.

After passing the epididymis sperm can be stored in the body of a man for several weeks, maintaining the ability to fertilize. But if the sperm is stored for too long, the sperm starts to degrade and die.