Testicular factors of male infertility
Almost 10% – 15% of couples are unable to have a baby after one year of unprotected regular intercourse which is usually defined as infertility. There are many causes for this, both in the male and female partners. Some of these relating to the male are hormonal disorders, lifestyle, physical and psychological problems, chromosomal abnormalities and genetic factors.
The testicles are the main reproductive organs in the male. These sex glands are also called testes or gonads. They are housed in the scrotum (a pouch of skin behind the penis). The testicles produce and store sperm. They are the main source of testosterone, the male hormone which affects reproductive organs and other male features such as voice tone, body and facial hair and shoulder width.
In the previous article, we looked at the pre-testicular factors affecting male infertility. This post focuses on the testicular factors and we will follow up with more information on post-testicular issues.
Seminiferous tubules are located within the testes and account for the concentration and volume of testosterone produced. The intertubular portions of the seminiferous tubules provide blood and immune responses. Leydig cells, an important component in the testis, produce testosterone in the presence of luteinizing hormone (LH). These leydig cells are adjacent to the seminiferous tubules in the testicle. Lymphatic and blood vessels, nerves, immune cells, connective tissue and fibroblasts (hormonal factors which regulate growth and development of reproductive organs) are other intercellular components.
Spermatogenesis is the production of mature spermatozoa. These mature spermatids are released into the lumen (innermost part) of the seminiferous tubules. These cells or spermatozoa have low motility and are transferred to the epididymis. This passage through the epididymal duct is vital for maturity of the cells and their ability to move. From here, the sperm travels to the vas deferens, a long tube connecting the epididymis to the pelvic cavity, just behind the bladder. The mature sperm is transported from the vas deferens to the urethra, in preparation for ejaculation.
Sperm disorders, where problems occur with the production and maturity of sperm, are the main causes of male infertility. The defects in sperm can be varied:
- Sperm defects – Sperm DNA damage or SDF (sperm DNA fragmentation) is the major cause of defective sperm function.
- Teratospermia – abnormally shaped or immature sperm
- Asthenospermia – less motility or where the sperm is unable to move properly
- Oligospermia – a low sperm count
- Azoospermia – a complete absence of sperm in the semen.
These disorders can be due to the following:
- Endocrine or hormonal disorders: The hormone axis for male reproduction consists of 3 main components – the hypothalamic, pituitary and testicular glands. Any abnormality in the system can lead to a lack of testosterone which will stop sperm production.
- Genetic diseases: Many are associated with sperm abnormalities.
- Testicular factors: Undescended testicles, trauma to the testicles, testicular cancer or prior chemotherapy could affect sperm production.
- Lifestyle and environmental factors: Smoking, alcohol, drug use, excessive heat or tight underwear could contribute to sperm disorders.
Diagnosis and treatment: A semen analysis is usually the basic test for diagnosing male infertility and semen quality. The measurements of sperm volume, concentration, motility and appearance can be determined. Based on the results of the semen analysis, various treatments can be suggested by the concerned specialist. A sperm DNA Fragmentation test can reveal the quality of the sperm DNA even when a normal semen analysis report is obtained. We, at Andrology Centre, offer the Sperm DNA Fragmentation test.
The Semen Analysis report and Sperm DNA Fragmentation Test report can help guide the couple and the Andrologist or Infertility Specialist on further treatment options.