According to the best sexologist in Delhi, there are numerous factors that can cause male infertility as a result of their effect on the generation and maturation of sperm in the testicles themselves, generating oligozoospermia (low concentration of sperm in semen), asthenozoospermia (low mobility of sperm), teratozoospermia (abnormal in sperm morphology) or secretory azoospermia (no sperm are produced in the testes).

The most common causes of male infertility of testicular origin include the following:

• High testicular temperature: the normal temperature of the testicles should be between 35.5º and 36º. Any elevation above these figures has a negative impact on the sperm maturation process that begins in the seminiferous tubules.
• Toxic agents: there are numerous environmental factors to whose exposure the testicles can see altered the activity of Sertoli cells, which play an essential role in the transformation of spermatidine into mature sperm: tobacco, environmental pollution, pesticides, consumption of meat from animals hormonalized with estrogens, use of certain drugs, radiotherapy, professional exposure to toxic substances, etc.
• Klinefelter syndrome or XXY males: this is a chromosomal abnormality in which males have an extra X chromosome, causing a drop in testosterone that prevents sperm production (azoospermia). In addition, it causes anatomical alterations in the sexual organs, such as hypoganadism or micropenis.
• Other genetic factors: in recent times, genetic alterations have been detected in areas of the Y chromosome that negatively affect the spermatogenesis process, causing oligospermia or azoospermia. This is the reason that in assisted reproduction clinics men with a sperm concentration of less than five million.
• Trauma: strong blows to the testicles can affect the mechanisms of sperm production and maturation.
• Testicular pathologies: there are different diseases that affect the testicle and that condition the correct production of sperm:

–  Varicocele: is responsible for 20% of cases of male infertility that are detected in assisted reproduction clinics. It is characterized by venous valve insufficiency of the spermatic veins and, depending on its severity, can cause teratozoospermia and oligozoospermia.
–  Cryptorchidism: It is a problem that occurs essentially in boys as one or both testicles do not descend into the scrotum, so, among other things, they are subjected to temperatures above 36º, which affects the quality of the sperm. It can also occur after puberty as a result of mumps.
–  Hydrocele: it is the accumulation of fluid around the testicle, which causes a significant increase in the overall volume of the scrotal bag that contains it. In principle, it may not compromise fertility, but there is a risk of complications that can cause infertility.
–  Genitourinary infections: they can cause testicular atrophy, obstruction of the seminal tract, generation of antisperm antibodies or compromise the accessory glands. They account for 5% of cases of male infertility, although some studies indicate that in 15% of men the semen analysis offers positive results.