Different Forms And Causes Of Male Infertility
Infertility is a common problem that most couples don’t consider until they experience it. Many factors cause and increase your risk of infertility and can harm your chances of getting pregnant.
An estimated 15% of American heterosexual couples encounter fertility issues when trying to conceive.1 Infertility is the inability to conceive after one year of frequent, unprotected sex.
Table of Contents
It is difficult to determine how widespread male infertility is.2 Overall, about 8%-20% of infertility cases are caused by male reproductive factors, and in about 35% of cases, the cause is attributed to both male and female factors.3,4 In about 50% of cases, the cause of male infertility is unknown.5
Genetic changes in the DNA sequence of the male (Y) chromosome can cause infertility. Klinefelter’s syndrome (XXY) is an example. A genetic cause of infertility is suspected when a male has very small testes and very low to absent sperm count.
Other inherited conditions that can cause male infertility include: 6
- Cystic fibrosis
- Kallmann syndrome
- Chromosomal abnormalities that affect testicular function
- Small deletions of the genetic code on the Y chromosome
Underlying Medical Conditions
Diabetes, cancer, systemic infections, autoimmune disorders, celiac disease, cystic fibrosis, and medical conditions that cause increased oxidative stress can all contribute to male infertility.
Sexually transmitted infections that are undiagnosed and untreated can also contribute to male infertility. They can cause inflammation of the epididymis or testes and cause scarring.
Lifestyle factors can also contribute to male infertility, including:7
- Obesity is associated with decreased testosterone and reduced sperm counts. Researchers found that people who engage in regular, moderate levels of exercise and choose a healthy diet comprising whole foods are less likely to have infertility.
- Illicit substance use can also affect sperm function. Marijuana directly affects sperm function by acting on the cannabinoid receptors.
- Tobacco use is associated with decreased semen volume, sperm count, and sperm motility. Toxins found in cigarette smoke and nicotine are both thought to impact fertility.
- Excessive alcohol consumption causes decreased testosterone levels and impacts all aspects of sperm function. Binge drinking, especially, should be avoided.
Physical Trauma/Surgical Side Effects
Injury, physical trauma, and surgical complications can also cause male infertility if they affect how sperm are produced and transported through the male reproductive system. Severe testicular trauma or scar tissue in any of the ducts can prevent sperm from passing through the male reproductive tract.
Excessive heat exposure can also cause male infertility. Potential causes include wearing tight underwear, placing a laptop on your lap, an undetected varicocele, or frequent hot tub or sauna use.
With ejaculation, sperm in semen is forcefully expelled from the vas deferens, through the ejaculatory duct, and out the urethra. With retrograde ejaculation, the muscle that keeps ejaculate from passing backward into the bladder fails to contract, and semen passes into the bladder instead of out the penis through the urethra.
Besides infertility, another clue that a man has retrograde ejaculation is a cloudy appearance to his urine right after sex. This is because the urine contains sperm.
The testes move from the abdominal cavity into the scrotum during fetal development. If they remain in the abdomen and do not fully descend into the testes, this increases the risk of poor sperm quality. The longer the testes remain undescended, the greater the risk to future fertility.
Typically, undescended testes are detected during well-child exams during the first year of life. Surgical repair of undescended testes is usually recommended before age one year. Early surgical intervention can reverse some of the hormonal, genetic, and developmental abnormalities associated with undescended testes.8
Sperm must pass from the testes, where they are produced, through the epididymis, where they are stored until they mature. With ejaculation, sperm are forcefully expelled from the epididymis into the vas deferens through the ejaculatory duct, leaving the penis after traveling the length of the urethra.
Abnormalities, narrowing, or scarring along these ducts can cause infertility.
Genetic predisposition, medical conditions, medications, and aging are a few factors that can affect your hormone levels. Endocrine organs and the hormones they produce have widespread effects. Abnormalities of the hypothalamus, pituitary, thyroid, and adrenal glands can cause male infertility.
To naturally regulate your hormones:
- Get 7 to 9 hours of restful sleep
- Do regular strength-building exercises
- Watch your weight
- Address your stress
- Avoid environmental toxins
- Consume a nutritious diet
Physical, psychological, and sexual health are all intertwined. Decreased libido and erectile dysfunction, or other conditions that interfere with sex, can cause infertility. If making lifestyle changes does not improve your sexual health, talk to an Invigor Medical treatment specialist to learn more about prescription sexual-health treatments such as:
- Passion: improves mood, erectile function, and libido and fosters intimacy
- PT-141: improves libido and erectile function
- Tadalafil-Oxytocin: increases libido and erectile function
Aging (over age 40-45) is a risk factor for hormonal disorders and infertility. Male aging is associated with a decrease in sperm count and motility.9 After receiving a complete physical exam, talk to your doctor about options for age management.
Sperm are normally protected from the immune system. When these barriers are breached, the immune system can form antibodies to sperm because they are genetically different from body cells.
Anti-sperm antibodies are immune cells that bind to sperm cells and can cause clumping. Many men have anti-sperm antibodies, but they do not cause infertility. Anti-sperm antibodies are suspected of causing infertility when sperm show slow motility and are clumped together in a semen sample.
When anti-sperm antibodies cause infertility, sperm washing followed by in-vitro fertilization is one treatment option. Using corticosteroids to decrease the immune response is another.10
Cancers and nonmalignant tumors that directly affect the male reproductive system or organs that release hormones, such as the pituitary gland, can affect fertility. Chemotherapy or radiation treatment used to treat cancers can also cause male infertility.
Medication Side Effects
Some medications can cause infertility by affecting hormone production or sexual function.
- Anabolic steroids: testosterone and its synthetic derivatives are used by some people to increase muscle mass and decrease body fat. These medications blunt natural testosterone production.11 In one study, bodybuilders had significantly reduced percentages of normal, motile sperm when compared to healthy volunteers.12
- Antidepressants: these medications can decrease sperm concentration and motility, increase DNA fragmentation, and decrease reproductive organ weights.13
- Other medications: some chemotherapeutic drugs and medications used to treat arthritis or ulcers can impair sperm production and decrease male fertility. Cannabinoids, opioids, and psychotropic drugs can inhibit gonadotropin-releasing hormone, which affects sperm production and maturation.8
Malformed sperm typically cannot survive the long trip from the male reproductive system through the female reproductive system to fertilize an egg.
Azoospermia is the inability to produce sperm.
Globally, sperm counts have decreased over recent decades. The mean sperm count has declined by 51.6% between 1973 and 2018. The rate of decline increased after 2000, from 1.16% per year to 2.64%.14
The exact cause of a global decline in sperm count is not fully understood but may be due to long-term exposure to environmental toxins such as pesticides, plasticizers, and radiation.8
Varicoceles are the most common cause of male infertility. Almost 15% of men and 40% of men with infertility have varicoceles, which are swollen veins.15 How varicoceles are related to infertility is not fully understood, but it may be due to blood reflux or a temperature change. Varicoceles can cause reduced sperm quality and quantity.
Ideally, sperm production occurs at around 93.2ºF. When blood vessels around the testes are enlarged, temperature may increase slightly, impacting testosterone levels and sperm production. If a varicocele is noted on a physical exam, it may be repaired surgically or using a percutaneous embolization technique. Varicocele repair has a low risk of complications, and in most cases, semen quality and fertility improve in 3 to 6 months.15
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
- Thonneau P, Marchand S, Tallec A, Ferial ML, Ducot B, Lansac J, Lopes P, Tabaste JM, Spira A. Incidence and main causes of infertility in a resident population (1,850,000) of three French regions (1988-1989). Hum Reprod. 1991 Jul;6(6):811-6. doi: 10.1093/oxfordjournals.humrep.a137433. PMID: 1757519.
- Barratt CLR, Björndahl L, De Jonge CJ, Lamb DJ, Osorio Martini F, McLachlan R, Oates RD, van der Poel S, St John B, Sigman M, Sokol R, Tournaye H. The diagnosis of male infertility: an analysis of the evidence to support the development of global WHO guidance-challenges and future research opportunities. Hum Reprod Update. 2017 Nov 1;23(6):660-680. doi: 10.1093/humupd/dmx021. PMID: 28981651; PMCID: PMC5850791.
- Centers for Disease Control and Prevention (2021). Infertility FAQs. Retrieved from http://www.cdc.gov/reproductivehealth/infertility
- Hull MG, Glazener CM, Kelly NJ, Conway DI, Foster PA, Hinton RA, Coulson C, Lambert PA, Watt EM, Desai KM. Population study of causes, treatment, and outcome of infertility. Br Med J (Clin Res Ed). 1985 Dec 14;291(6510):1693-7. doi: 10.1136/bmj.291.6510.1693. PMID: 3935248; PMCID: PMC1418755.
- Jose-Miller AB, Boyden JW, Frey KA. Infertility. Am Fam Physician. 2007 Mar 15;75(6):849-56. PMID: 17390595.
- Agarwal A, Baskaran S, Parekh N, Cho CL, Henkel R, Vij S, Arafa M, Panner Selvam MK, Shah R. Male infertility. Lancet. 2021 Jan 23;397(10271):319-333. doi: 10.1016/S0140-6736(20)32667-2. Epub 2020 Dec 10. PMID: 33308486.
- Krzastek, S. C., Farhi, J., Gray, M., & Smith, R. P. (2020). Impact of environmental toxin exposure on male fertility potential. Translational Andrology and Urology, 9(6), 2797–2813. https://doi.org/10.21037/tau-20-685
- Leslie SW, Soon-Sutton TL, Khan MAB. Male Infertility. [Updated 2022 Nov 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK562258/
- Collodel, G., Ferretti, F., Masini, M. et al. Influence of age on sperm characteristics evaluated by light and electron microscopies. Sci Rep 11, 4989 (2021). https://doi.org/10.1038/s41598-021-84051-w
- Antisperm Antibodies —. (n.d.). Male Infertility Guide. Retrieved February 3, 2023, from https://www.maleinfertilityguide.com/antisperm-antibodies
- El Osta R, Almont T, Diligent C, Hubert N, Eschwège P, Hubert J. Anabolic steroids abuse and male infertility. Basic Clin Androl. 2016 Feb 6;26:2. doi: 10.1186/s12610-016-0029-4. PMID: 26855782; PMCID: PMC4744441.
- Knuth UA, Maniera H, Nieschlag E. Anabolic steroids and semen parameters in bodybuilders. Fertil Steril. 1989 Dec;52(6):1041-7. doi: 10.1016/s0015-0282(16)53172-0. PMID: 2512180.
- Beeder, L.A. and Samplaski, M.K. (2020), Effect of antidepressant medications on semen parameters and male fertility. Int. J. Urol., 27: 39-46. https://doi.org/10.1111/iju.14111
- Levine H, Jørgensen N, Martino-Andrade A, Mendiola J, Weksler-Derri D, Jolles M, Pinotti R, Swan SH. Temporal trends in sperm count: a systematic review and meta-regression analysis of samples collected globally in the 20th and 21st centuries. Hum Reprod Update. 2022 Nov 15:dmac035. doi: 10.1093/humupd/dmac035. Epub ahead of print. PMID: 36377604.
- Report on varicocele and infertility: a committee opinion. (2014). Report on varicocele and infertility: a committee opinion. Fertility and Sterility, 102(6), 1556–1560. https://doi.org/10.1016/j.fertnstert.2014.10.007