Oligospermia represents a significantly reduced probability of a man conceiving a child. For a healthy male, conditions like oligospermia, erectile dysfunction, and premature ejaculation can inflict immense psychological distress. Under normal circumstances, only sperm with forward motility can ensure they reach the ampulla of the fallopian tube to fertilize an egg.After ejaculation, sperm motility is initially restricted before semen liquefaction. Once liquefied, sperm immediately exhibit strong motility. If factors impair sperm motility—particularly forward movement—sperm cannot reach the egg within the optimal timeframe, preventing fertilization.
What are the root causes of asthenospermia?
1. Varicocele
Caused by blood stasis in dilated veins, impaired microcirculation, insufficient nutrient supply, reduced oxygen partial pressure, inadequate energy production, and endocrine dysfunction.
2. Abnormal semen liquefaction causing asthenospermia
Failure of semen to liquefy or excessive viscosity is one cause of asthenospermia-related male infertility. A significant factor may be impaired sperm motility.In seminal plasma that fails to liquefy, elongated fibrin strands form a network that reduces space for sperm movement, trapping sperm. Additionally, coarse fibers connected by numerous fine fibers create a web-like structure, potentially mechanically restricting sperm forward motility.
3. Infection
Acute or chronic inflammation of reproductive tract structures or glands—such as the epididymis, vas deferens, seminal vesicles, or prostate—can impair sperm motility.
4. Immunological Factors
Anti-sperm antibodies (AsAb) can disrupt sperm fertilization through multiple mechanisms.The impact on sperm motility may occur when AsAb binds to the sperm tail, impairing motility and reducing penetration capacity. This has been confirmed by studies showing significantly diminished ability to penetrate cervical mucus when anti-sperm antibodies targeting the sperm tail are present.
5. Endocrine Factors
Endocrine hormones not only influence spermatogenesis and maturation but also affect sperm motility.
6. Chromosomal Abnormalities
Abnormalities in autosomes and sex chromosomes affect not only sperm count but also sperm viability and progressive motility.
7. Environmental Factors
Exposure to environmental pollutants, radiation, and certain chemicals may impair sperm motility and fertility.
8. Genetic Factors
Genetic disorders such as Klinefelter syndrome (trisomy XY) and Turner syndrome (XO) can cause severe sperm abnormalities and infertility.
9. Immunological Factors
Antisperm antibodies (AsAb) may bind to the sperm tail, impairing motility, penetration capacity, and fertilization potential. This has been demonstrated by studies showing significantly reduced ability to penetrate cervical mucus when anti-sperm antibod
6. Chromosomal Abnormalities
Abnormalities in autosomes and sex chromosomes affect not only sperm count but also sperm viability and progressive motility.
Who is to blame for low sperm success rates?
Before addressing what constitutes a normal sperm survival rate, let's first identify the eight primary culprits behind low sperm success rates.
1. Inflammation in the epididymis, seminal vesicles, or prostate causing semen abnormalities.
2. Severe hypoxia in the testes due to impaired venous blood return.
3. Insufficient semen volume significantly impacts sperm viability.
4. Production of anti-sperm antibodies in the body causing sperm agglutination or immobilization.
5. Impaired testicular development affecting sperm viability.
6. Trace element deficiencies impacting sperm survival rates.
7. Prolonged abstinence causing excessive sperm density, high dead sperm counts, and poor motility.
8. Mycoplasma infections severely impairing sperm viability.