Male infertility arises either due to abnormal production of spermatogenesis or inadequacies in their transport. Many medical as well as environmental reasons influence these two factors. Some of the common causes of male infertility are as follows:
The medical term for infection of testes is called orchitis. The epididymis can also get infected and the condition is named epididymitis. Both these diseases happen due to bacterial attack and damage sperm production and maturation. Some sexually transmitted diseases, such as gonorrhea, also interfere with the ability to make sperm. Similarly, the measles virus damages testicular tubes. So, men with a history of measles in their childhoods may have low fertility levels.
As the testes develop in the male pelvis, they need to fall in the scrotum. Their path from the pelvis to the scrotum involves many structures in the way. Any abnormality in these structures can impede their descent. Testosterone regulates this process, and its low levels also result in this condition. The surgical correction is done, but the testes may not fully regain their ability to form sperm. Resultantly, either the sperm analysis shows low sperm count or sperm of abnormal shape.
Varicocele is a medical condition in which blood vessels of testes do not function well. Due to blockage in vessels, the blood and fluids accumulate in the tissue. The testes and scrotum swell and become painful. It impacts sperm production as well as their movement to the urethra.
Three tubes are involved in the transport of sperm and semen:
Blockage or injury of any of these tubes influences male fertility. The obstruction results in a low concentration of sperm in the ejaculate.
The congenital absence of vas deferens also hinders sperm transport from testicles to the urethra. In this situation, the vas deferens is either absent or not fully grown at birth.
Genes determine the development of the reproductive system in a male fetus. Human males possess XY while females have XX chromosomes. The Y chromosome defines male sex. In Klinefelter's syndrome (XXY), humans have two X and one Y chromosome. Due to an extra X chromosome, the female factor dominates and the male reproductive system does not fully mature. A faulty reproductive system interferes with fertility. Therefore, ruling out genetic disorders is an integral part of diagnosing the cause of fertility.
It is an uncommon cause of infertility in which sperm cells get killed by semen. The semen contains proteins that perceive sperm as foreign particles. These proteins attack sperm, reducing their count to minimal. An antibody test of the semen confirms the presence of anti-sperm antibodies.
Proper positioning of the penis is crucial for its entry into the vagina. The inability to maintain an erection of the penis is knows as erectile dysfunction, and can interfere with keeping a healthy sex life.
Structural abnormality like hypospadias also plays a role. Hypospadia is the mal-positioning of the penile opening, where the urethra opens on the underside or base of the penis instead of its tip.
Weight has a noticeable effect on male fertility. In obese individuals, testosterone levels decline, which results in decreased sperm concentration per ejaculate. The fatty tissue in the scrotum also makes testes warm and diminishes sperm quality. The research suggests that a 10% decrease in male fertility occurs for every 9kgs weight gain.