Factors that may lead to male infertility

Infertility is a health worry that affects approximately one out of every six couples, or 15% of couples. Infertility is the diagnosis given to a couple who are unable to conceive over the course of a year. If the problem stems from the man, there is said to be male infertility. If it stems from the woman, there is female infertility. In a third of infertility cases, the man is infertile; in another third, the woman is infertile; and in the last third, either both are infertile or no cause can be found.

Male infertility stems from factors such as: low sperm production, abnormal sperm function or blockages that hinder the delivery of sperm, hormone imbalances or blockages, absence of some of the ducts in the male reproductive organs, lifestyle factors and age-related factors. Azoospermia or the inability to produce sperm is the cause of approximately 15% of male infertility cases. The inability to conceive a child is the main sign of male infertility, and may be the sole sign. Let's take an in depth look at the causes of male infertility.

1. Damage to the testes

The testes are the glands that produce sperm and testosterone (the main male sex hormone). Damage to the testes is the cause of 30-40% of the cases of male infertility. The testes can get damaged from infections such as mumps and HIV. Cancer treatments, testicular torsion, testicular trauma, a history of testicular cancer, undescended testicles and others can also affect normal sperm production by the testicles. Epididymitis which can be caused by bacterial infection, genito-urinary surgery and other non-infectious causes can lead to testicular atrophy and obstructive azoospermia hence negatively influencing fertility. Obstructive azoospermia occurs when a man's semen is void of sperm because of a physical obstruction of the genital tract.

2. Sperm disorders

Sperm disorders include: azoospermia, oligospermia, asthenospermia, and teratospermia. With oligospermia, sperm are produced in abnormally low numbers. With asthenospermia, sperm are unable to move properly. Teratospermia occurs when sperm are immature or abnormally shaped. Genetic diseases also cause sperm abnormalities. Such genetic causes of sperm disorders include chromosomal abnormalities and Y chromosome microdeletion (YCM). Klinefelter syndrome is a chromosomal abnormality which men have an extra X sex chromosome (XXY). Klinefelter syndrome usually occurs randomly, and is characterized by infertility and small testicles. Y chromosome microdeletion occurs when small sections of the Y chromosome are missing or deleted and is common in men with azoospermia or severe oligospermia.

3. Hormone imbalances

Infertility in men rarely stems from a hormonal deficiency. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) induce testosterone and sperm production in the testes. The pituitary gland in the brain produces LH and FSH. The presence of a pituitary tumor disrupts the normal functioning of the pituitary gland, hence affecting the production of hormones like LH and FSH. Reduced production of LH in turn affects the production of testosterone, while reduced production of FSH affects sperm production. Low testosterone can reduce a man's sex drive and cause erectile dysfunction.

4. Immunologic infertility

In such cases, a man's immune system attacks sperm (with the production of antisperm antibodies) as though they were invading cells, which impairs sperm motility. Antisperm antibodies (ASA) can interfere with the fertilizing ability of spermatozoa. They can also reduce the concentration of spermatozoa and induce sperm agglutination. ASA also affect sperm penetration of cervical mucus and induce abnormal swimming behavior within cervical mucus.

5. Age, lifestyle and environmental factors

Exposure to toxic chemicals can disrupt the hormones that control the reproductive system and affect sperm quality. PFCs are a group of commonly found environmental chemicals. Higher levels of exposure to PFCs results in a significant reduction in sperm quality and changes in reproductive hormone levels.

Lifestyle factors which affect male fertility include: cigarette smoking, alcohol intake, use of illicit/recreational drugs, obesity, psychological stress, dietary practices, advanced paternal age, coffee consumption, testicular heat stress, lack of sleep and exposure to electromagnetic radiation from mobile devices. 

Alcohol affects male fertility by altering sperm count, size, shape and motility. Men who drink heavily have lower testosterone levels, FSH, LH, and higher estrogen levels, which reduce sperm production.

Recent research has proven that men who carry cellphones in their pants (trousers) have reduced chances of fathering offspring. Being exposed to radio-frequency electromagnetic radiation from carrying mobiles in trouser pockets negatively affects sperm quality.

Sleep deprivation and stress result in low testosterone levels. A study revealed that men who fell asleep past midnight had higher levels of anti-sperm antibodies than those who went to bed between 10 pm and midnight. Research also suggest that men who sleep for less than six or more than nine hours a night have a 42% reduced probability of conception in any given month.

Testicular heat stress which results from scrotal hyperthermia is a critical factor for male infertility. Testicular tissues are extremely sensitive to even mild overheating. Studies have shown that a mild rise in temperature leads to a dramatic decrease in total sperm count and sperm motility. It also degrades the morphology of the surviving sperm.

Smoking affects every stage of the reproduction process. Men who smoke can have problems getting and maintaining erections. Low sperm count, abnormally shaped sperm, and decreased ability to fertilize eggs are all effects of smoking on sperm. Children born to men who smoked more than 20 cigarettes a day at the time of their conception have a higher risk of childhood leukemia. Marijuana increases impotence, reduces sperm count and can interfere with a man's ability to ejaculate.

Overweight men are more likely to face challenges in getting and keeping an erection. Such men also have poorer sperm quality. 

Men may need to start thinking about biological parenthood before they turn 40 as their fertility faces a decline with age as well. Moreover, older men have greater chances of fathering offspring at higher risk for birth defects and developmental disorders. 

What's more, the older a man is when his partner conceives, the more likely she is to miscarry. According to recent studies, as men get older, each successive year accounts for a 2.6% decline in sperm concentration, a 0.3% decrease in motile sperm number, and a 0.7% decrease in the percentage of normal sperm morphology. A 2005 review found that the highest IQ was found at paternal ages of 25–44; fathers younger than 25 and older than 44 tended to have children with lower IQs.

6. Sexually transmitted infections (STIs)

Chlamydia is the STI that causes male infertility the most. If left untreated, chlamydia can cause permanent scarring and blockages in the centers associated with sperm production. It also causes sperm to be malformed and immobile. Gonorrhea can result in epididymitis which may lead to infertility.

A man is advised to seek medical attention if after a year of regular, unprotected intercourse, he has been unable to impregnate his partner. A man should also consult a doctor if:

·        He has a history of testicular, prostate or sexual problems,

·        He has undergone cancer treatment,

·        He has family members who have infertility issues,

·        He has a low sperm count,

·        He has small testicles or a swelling in the scrotum.