What Causes Low Sperm Motility in Men?
Aug 20, 2021
Source: Cainiu Health
Dr. Li Mingchuan
Introduction
1. Reproductive tract infections—such as epididymitis, seminal vesiculitis, vasitis, and prostatitis—in males, involving acute or chronic inflammation of the genital tract or associated glands.
2. Immunological factors—anti-sperm antibodies significantly impair sperm motility by interfering with their binding to the sperm tail.
3. Varicocele—impaired blood circulation in the testes and epididymis leads to elevated local temperature.
In men with low sperm motility, identifying the specific underlying cause is the first step. In many cases, the condition is closely associated with infections of the reproductive organs or immune system dysfunction. Once the cause is identified, targeted treatment can be initiated. However, treating this condition is often challenging and may require long-term management to restore overall health—making psychological adjustment equally important. So, what causes low sperm motility in men? Below, we address this question.
What Causes Low Sperm Motility in Men?
1. Reproductive Tract Infections
Acute or chronic inflammation affecting male reproductive structures—including the epididymis, seminal vesicles, vas deferens, and prostate—can significantly impair sperm motility. Additionally, abnormal semen liquefaction (e.g., failure of semen to liquefy or excessive viscosity) is another contributing factor to reduced sperm motility and a known cause of male infertility.
2. Immunological Factors
Anti-sperm antibodies substantially impair sperm motility by interfering with antibody binding to the sperm tail, thereby hindering motility and reducing sperm’s ability to penetrate the oocyte. Moreover, prolonged abstinence—i.e., extended periods without ejaculation—may lead to elevated sperm concentration, increased numbers of non-viable (dead) sperm, and diminished overall sperm motility.
3. Varicocele
Varicocele disrupts blood circulation in the testes and epididymis, leading to localized temperature elevation and accumulation of toxic metabolites—all of which compromise sperm motility. Other contributing factors include deficiencies of trace elements (e.g., zinc, copper, magnesium) in seminal plasma, smoking, alcohol consumption, and certain medications—all of which may contribute to asthenozoospermia (reduced sperm motility).
Knowledge Extension: Standard Criteria for Sperm Quality
1. Sperm Motility
During normal sexual intercourse, semen deposited in the vagina cannot directly achieve fertilization. Instead, sperm must actively swim through the female reproductive tract to reach the uterus and fallopian tubes, where fertilization occurs upon encountering the oocyte. Therefore, sperm motility is critically important. A forward progressive motility rate of ≥32% is generally considered acceptable; a rate ≥50% is regarded as optimal.
2. Sperm Concentration
Normal ejaculate volume ranges between 2–7 mL; volumes outside this range may adversely affect fertility. A sperm concentration of ≥20 million/mL is considered within the normal range. Furthermore, the proportion of morphologically normal sperm should be ≥4% (i.e., abnormal morphology should not exceed 96%), as excessively high teratozoospermia rates may impair fertilization capacity. Under normal conditions, semen color appears grayish-white or slightly yellow.
The above outlines the primary causes of low sperm motility in men. We hope this information proves helpful.
