Disclaimer Note: While both men and women can be infertile, this article focuses on male infertility, it’s most common causes and treatments. For information on female infertility click here.
Overview of Male Infertility
Male infertility occurs when a man’s sperm cannot successfully fertilize his partner’s egg. Typically, infertility in men is correlated with any health issue that lowers the chances of his female partner getting pregnant 5. Male infertility is responsible for 40% of failed pregnancies, while 40% are female infertility issues, and 20% of the time there are complications with both partners 3. Male infertility is typically linked to anatomical or hormonal complications that hinder the production of healthy sperm. Infertility in men can be diagnosed by a simple semen analysis and treatment is available in the form of surgical procedures as well as hormonal medications.
Medical Diagnosis of Male Infertility
Azoospermia: a condition in which a man does not have any measurable level of sperm in his semen and contributes to 5% of infertility cases. Typically, this absence of sperm is linked to sperm production itself or an anatomical blockage that doesn’t allow the sperm to reach the rest of the ejaculate.
Oligospermia: an issue defined as low sperm concentration or low “sperm count.” The World Health Organization suggests that a sperm count of less than 20 million sperm/mL is considered diagnosable with Oligospermia (WHO).
Causes and Treatments
Male infertility is caused by hormonal imbalances, physical problems, psychological problems, and behavioral or environmental factors 4. A Stanford University study found that fertility reflects a man’s overall health, and that men who live a healthy lifestyle will more likely produce healthy sperm 4. Furthermore, it is this sperm production process that is most important when examining what causes male infertility. If the sperm production process is disrupted, then the risk of becoming infertile increases. Making mature, healthy sperm that can travel depends on many factors. Complications in the production process can stop cells from growing into sperm, keep the sperm from reaching the egg, and even fluctuate the temperature of the scrotum, which also affects fertility 5.
While a percentage of male infertility is caused by hormonal problems, it is important to understand how lifestyle choices can affect the ability to produce healthy sperm. Similar to the female ovulation process, the hypothalamus-pituitary endocrine system regulates the chain of hormonal signals that enables the testes to produce and effectively distribute sperm. Furthermore, complications with the production of the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) can fail to stimulate the testes and hinder their ability to produce testosterone, which is then affects healthy sperm production. We must also understand the hypothalamus and its role in secreting gonadotropin-releasing hormone (GnRH), which acts on the anterior pituitary gland and stimulates the release of FSH and LH. FSH acts on the testes and encourages spermatogenesis within the seminiferous tubules, which is the process of male cells forming into spermatozoa by mitosis or meiosis 2. LH reacts with leydig cells to produce testosterone, which is important because levels of this hormone are 50 times higher within the testes than in the bloodstream 2. If there are complications or discrepancies in the production and distribution of GnRH, LH, and FSH, then there is increased chance that a man may experience infertility due to inadequate sperm production.
Hormonal disorders contribute to the complications and discrepancies described above. Hypothyroidism or low thyroid hormone levels can cause poor semen quality, poor testicular function and may disturb one’s libido 4. Hypothyroidism is found in about 1 percent of infertile men 4. Congenital Adrenal Hyperplasia occurs when increased levels of adrenal androgens, (which may cause low sperm count) an increased number of immature sperm cells, and low sperm motility, suppress the pituitary gland. These are only a couple of hormonal disorders that influence a male’s ability to produce quality sperm, yet many exist, all with varying degrees of severity.
These hormonal complications can be linked to lifestyle choices that inhibit the male’s body to function properly in regards to healthy sperm production. Lifestyle choices include smoking, chronic alcohol abuse, anabolic steroid use, overly intense exercise, malnourishment, exposure to environmental toxins, anemia, and even stress. While all these may not cause infertility, they will increase the chances of becoming infertile and therefore are important in analyzing what causes infertility. The roles that lifestyle choices play is their ability to hinder the sperm production process that is very complex and relies on a healthy body to in turn produce healthy sperm.
On the other hand, physical problems or anatomical complications are typically linked with testicular damage. Painful events either in the form of minor or major damages to the testes or scrotum should be taken seriously. These events include any penetrating injury to the scrotum, bruising and/or swelling of the scrotum, trouble peeing or blood in the urine, and fevers after testicular injury 5. Trauma to the scrotum can cause damages to the vital internal organs (testes, epididymis, vas deferens etc.) that are essential for sperm production. Sperm production is not the only process that testicular trauma can hinder. Damages to the scrotum and testicles can also disrupt the pathway that sperm needs to travel from the testes to the tip of the penis 4. These physical problems or anatomical complications are usually characterized by a low sperm count and or abnormal sperm morphology 4.
The most common physical problems include varicocele, damaged sperm ducts, testicular torsion, infection and disease, retrograde ejaculation, and Klinefelter’s syndrome. Varicocele is an enlargement of the internal spermatic veins that drain blood from the testicle to the abdomen and back to the heart 4. The varicocele develops when the one-way valves of these veins are damaged causing an abnormal back flow of blood from the abdomen into the scrotum, which creates a hostile environment for sperm development 4. Variococles can be diagnosed by a physical examination of the scrotum and are most successfully treated by corrective surgery 4.
Damaged sperm ducts restrict the transportation of sperm from the testicles to successful ejaculation out of the penis. This can be the result of genetic or developmental complications that block one or both of the tubes, which are called vas deferens 4. Furthermore, scarring from infections or diseases can block the epididymis, which stores sperm before it travels through the vas deferens on to the seminal vesicles. Some of these infections and diseases include mumps, tuberculosis, gonorrhea, influenza, smallpox, and syphilis 4. In the case of tubular blockage, complications are usually treated by hormonal replacement therapy and surgery in the case of tubular blockage 4.
Testicular torsion is caused by a supportive tissue abnormality that allows the testes to twist inside the scrotum, which is characterized by extreme swelling 4. Similarly the “bell clapper deformity”, is when the testicles are not attached to the scrotum as usual and are more inclined to turn and twist within the scrotum. This is dangerous because this torsion shuts the blood vessels that feed the testes, which can lead to the complete loss of function if not attended to as soon as possible. However, if tended to early enough, testicular torsion can be corrected by surgery.
Retrograde ejaculation can contribute to male infertility through a malfunction of the bladder sphincter, which allows all or some of the ejaculate to enter into the bladder during climax rather than out of the body through the urethra. This results in what is called a “dry orgasm,” - when a male reaches sexual climax but may ejaculate very little to no semen depending on the severity of the torsion. If there is little to no semen in the ejaculate, then the chances of sperm reaching the egg for fertilization decreases drastically. Retrograde ejaculation is often corrected by medications such as decongestants that contract the bladder sphincter, or by surgery that reconstructs the bladder neck 4.
Klinefelter’s syndrome is a genetic condition in which each cell in the human body has an additional X chromosome 4. Men with Klinefelter’s have one Y and two X chromosomes, which result in testes too small to produce an adequate quantity of sperm 4. Previously, people considered men with Klinefelter’s as infertile. It wasn’t until 1996, that developments in microsurgical techniques and advances in artificial reproductive technologies allowed for more than 50% of Klinefelter’s patients to have their own children 1.
In many cases couples having problems getting pregnant believe it is due to infertility problems with the woman. In reality, the man is the cause of the inability to become pregnant a third of the time. Culturally, this is due to the fact that men often do not seek out medical assistance in regards to infertility complications 4. Semen analysis is a simple and harmless way to test for male infertility that aids in diagnosing the complications and selecting the best available treatment. In America, Planned Parenthood provides semen analysis services that may be partially covered under state funding.
1. "Klinefelter Syndrome Treatment & Management." Klinefelter Syndrome Treatment & Management: Medical Care, Surgical Care, Consultations. N.p., n.d. Web. 24 Nov. 2015. http://emedicine.medscape.com/article/945649-treatment.
2. "Male Fertility and Infertility." The Turek Clinic. N.p., n.d. Web. 24 Nov. 2015. <http://theturekclinic.com/services/male-fertility-infertility-doctor-tre....
3. The male side of infertility. (2006). National Women's Health Report, 27(6), 9. Retrieved from http://search.proquest.com/docview/236204861?accountid=14522
4. "What Causes Male Infertility?" Stanford Edu. Stanford University, n.d. Web. 24 Nov. 2015. <https://web.stanford.edu/class/siw198q/websites/reprotech/New%20Ways%20o....
5. "What Is Male Infertility?" Urology Care Foundation. American Urological Association, 2015. Web. 24 Nov. 2015. <http://www.urologyhealth.org/urologic-conditions/male-infertility>.
Last Updated on 24 November 2015.