Low sperm count, also known as oligospermia, is one of the common causes of infertility in men. According to the World Health Organization (WHO), oligospermia is when your sperm count is less than 15 million per milliliter. The normal sperm count ranges from 15 million to more than 200 million sperms per milliliter of semen. The complete absence of sperm is known as azoospermia. The sperm count plays a key role in fertility as having a low sperm count decreases the chances of fertilizing an egg, which in turn affects the chances of your partner to get pregnant.
Causes Of Low Sperm Count
There are numerous causes of low sperm count right from environmental factors such as industrial pollutants and lifestyle factors including smoking and weight to medical causes such as hormonal imbalance and infection. Here are a few common causes of low sperm count every man should be aware of!
Just like women, the risk of low sperm count and infertility increases with age. Although men can contribute to conception even after 40 years of age, there are several degenerative changes that occur in the germinal epithelium and Leydig cells, which play a key role in spermatogenesis (production of sperms). Moreover, there is a decrease in the production of testosterone level post 30 years, which is also known to affect sperm production. Also, the probability of having erectile dysfunction increases three times in men aged between 40 to 70 years, which in turn can lead to low sperm count and infertility.
It goes without saying that overweight and obesity have become a serious problem in adult men throughout the world. Overweight and obesity have been associated with an increased prevalence of azoospermia or oligozoospermia. Obese men are 3 times more likely to show a reduction in semen quality than men of normal weight. Studies have reported that serum testosterone and sex hormone-binding globulin (SHBG) decrease with increasing body mass index (BMI). People with a BMI greater than 25 kg/m2 were significantly associated with a 4.2%, 3.9% and 3.6% reduction in semen volume, total sperm number, and total motile sperm count, respectively.
Obesity negatively affects male reproductive potential by reducing sperm quality. Moreover, it also alters the physical and molecular structure of germ cells in the testes, which ultimately affects the maturity and function of sperm cells.
Cigarette smoke contains more than 7000 chemicals and reactive oxygen species (ROS), which impair sperm function, decrease sperm count and ultimately lead to male infertility. Smoking not only causes a decline in sperm quality but also affects sperm quantity. Moreover, the relationship between smoking and sperm concentration was dose-dependent. Men who smoked > 20 cigarettes per day experienced a 13–17% reduction in sperm concentration compared with nonsmokers[1,4].
Paternal smoking is also considered as a significant risk factor for in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) failure, which in turn can lead to a decreased assisted reproductive technology (ART) success rates.
Several studies have shed light on the effect of alcohol intake and low sperm count. Moreover, excessive intake of alcohol is not only found to be harmful to sperm motility but also affects the morphology (shape and structure) in a dose-dependent manner. Chronic alcohol intake has a detrimental effect on both semen quality and the levels of male reproductive hormones. Alcohol appears to interfere with the production of hormones namely follicle stimulating hormone, luteinizing hormone and testosterone along with impairing the functions of Leydig and Sertoli cells.
Stress not only affects your emotionally and physically but can also affect you sexually. The effect of stress on sex is not much known. Several studies have reported that stress can cause changes in Sertoli cells and the blood-testis barrier, which ultimately causes spermatogenesis to be suppressed. This in turn not only affects the secretion of the hormone testosterone secretion but also affects the sperm count, which explains the detrimental effects of psychological stress on spermatogenesis.
Hence, when stressed, the body releases cortisol, stress hormone, which is found to suppress testosterone levels and affect the sperm quality.
There are few studies which have reported the effects of recreational, sports and prescription drugs on spermatogenesis. The use of androgenic steroids in men can suppress the secretion of luteinizing hormone from the pituitary gland and thus, suppress the release of testosterone by the testes. Similarly, chronic use of recreational drugs such as cocaine and marijuana were found to be associated with low sperm counts.
Some of the chemotherapeutic drugs (medications used for cancer treatment) as well as certain medications used to treat kidney disease were also found to have adverse effects on the spermatogenesis. Also, the use of sulfasalazine, which is widely used for chronic treatment of irritable bowel syndrome can also cause low sperm count and infertility in men.
7. Scrotal overheating
The testes descend into the scrotum so that the temperature is maintained around 3–4°C below the body temperature. If this temperature is not maintained or if the testes don’t descend to the scrotum (a condition known as cryptorchidism), it can affect the production of the sperms and thus, lead to infertility. Moreover, anything that impedes loss of heart from the scrotum can affect testicular temperature can negatively affect spermatogenesis. Certain disorders such as varicocele in which the veins in the scrotal region are enlarged or febrile illness such as influenza can cause low sperm count.
Also, exposure to an exogenous heat source such as occupationally (bakers, welders, foundry workers), using a laptop, keeping the phone near the pelvic area or taking a regular hot bath can also affect sperm production.
8. Health problems
Right from infections to ejaculatory problems, there are several health problems that can interfere with sperm production. The infection that can affect the sperm count and production include sexually transmitted infections (STIs) such as gonorrhea or HIV. Also, inflammation of the epididymis or testicles can also affect sperm count.
Retrograde ejaculation is an ejaculatory problem in when the semen enters the bladder during orgasm instead of coming out from the penis. The conditions that can cause retrograde ejaculation and lead to low sperm count include diabetes, spinal injuries or surgery of the prostate or bladder.
It is wise to see a doctor if you are unable to conceive a child even after having unprotected sex for a year. If you experience problems in ejaculation, pain or discomfort in the testicular region or surgery of the testicle or penis, then consult your doctor as it could be the reason for low sperm count or infertility.
(The article is reviewed by Dr. Lalit Kanodia, General Physician)
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