Research published in Current Sexual Health Reports describes "male infertility" as significantly "understudied compared to female factors." Contrary to popular belief, approximately a third of all infertility cases can be attributed solely to the partner who is assigned male at birth. An additional third (in cases of heterosexual couples) can be attributed to both partners. Additionally, cisgender male fertility is on the decline — and has been for decades. According to a 2017 meta-analysis published in Human Reproduction Update, sperm counts decreased almost 60 percent between 1973 and 2011.
These statistics may bring alarmed patients into a reproductive specialist's care, but they do not mean bad news for every patient who is looking to start a family. By exploring common causes of infertility and debunking misconceptions, patients and their doctors can work together to understand their reproductive health.
The Importance of Semen Analysis
If a heterosexual couple has tried and failed to conceive for one year (with a cisgender female partner younger than 35) or six months (with a cisgender female partner older than 35), both partners should have a fertility workup.
For patients with external reproductive organs, this entails a semen analysis with a urologist or a reproductive endocrinologist. The semen is typically collected at the doctor's office, although it can be collected at home as long as the sample is kept at body temperature and arrives at the office within 45 minutes of ejaculation.
According to research published in the Journal of Urology, semen analysis should include:
How Age Plays a Role
Advanced maternal age is a known concern for patients assigned female at birth who want to give birth or produce healthy oocytes, but advanced paternal age can also present an obstacle.
Older cisgender men tend to have a higher incidence of chronic health issues — such as diabetes and high blood pressure — compared with cisgender women, and these conditions can affect their overall fertility. Additionally, patients often produce more sperm with DNA abnormalities with age, which can lead to miscarriages or birth defects.
Patients assigned male at birth maintain their peak fertility slightly longer than assigned female patients, as advanced paternal age is generally considered over 40 or 45 years old. However, unlike patients with internal reproductive organs, they never stop producing sperm except in cases of disease or structural damage.
The Influence of Lifestyle Factors
Many potential male infertility causes can be uncovered by asking a patient about their lifestyle. Smoking (both cigarettes and marijuana) can negatively impact motility, morphology and the presence of white blood cells.
Heavy alcohol consumption may reduce sperm production by causing hormonal imbalances, such as disparities in estrogen, follicle-stimulating hormone, luteinizing hormone and testosterone. Obesity can also cause hormonal imbalances, including potentially increasing estrogen and lowering testosterone.
Reproductive specialists should caution patients against over-the-counter testosterone supplements. Although they may improve sex drive, they can severely damage fertility — sometimes leading to azoospermia, such as in a case study published in Reviews in Urology.
Exposure to certain chemicals can also affect male fertility. Bisphenol A, a common chemical in many commercial plastics, may reduce sperm count, motility and vitality, reports a review published in Fertility and Sterility. A study published in Risk Management and Healthcare Policy, meanwhile, found that exposure to certain pesticides used with fruit and vegetables may lower sperm count and affect viscosity and morphology. Phthalates can reduce sperm count and motility, and exposure to the common solvent trichloroethylene, such as in the workplace or when using cleaning products, may also contribute to causing infertility, according to the Toxics Use Reduction Institute.
Correcting Common Myths
Some male patients may come to a provider with the misconception that the kind of underwear they wear affects their fertility. Because sperm-producing cells in the testes are approximately two degrees lower than body temperature, long-term exposure to heat may impact sperm production. However, wearing boxers or briefs does not change testicle temperature. However, patients with external reproductive organs should avoid sitting in a hot tub or keeping a laptop on their lap for extended periods of time.
Impotence is also often confused with infertility. Impotence is the inability to achieve an erection, making it a sexual dysfunction, according to the American Society for Reproductive Medicine. Infertility, on the other hand, concerns a problem with sperm quality, quantity or both. Although someone with sexual dysfunction may also deal with infertility, the two conditions are not the same.
Many patients incorrectly believe that abstinence improves sperm quality. This is far from the truth, especially if the patient already has a low sperm count. In fact, waiting longer than two or three days between ejaculations may actually decrease sperm quality. Instead, a landmark study published in Fertility and Sterility in 2004 suggests ejaculating daily. A 2016 study on subfertile men published in Reproductive Biomedicine Online also found that several parameters of semen analysis showed improvement in the second of two consecutive sperm samples taken thirty minutes apart.
Discussing Male Infertility With Patients
In many cases, improvements in semen parameters come with lifestyle changes and hormone therapy. If those are not the best approach for a particular patient's situation, microsurgeries may help extract sperm directly from the testicles.
Infertility can be a sensitive topic. Healthcare providers can deftly navigate these discussions by sticking with the facts — the percentage of patients impacted and the role of diagnostic testing — and suggesting actionable steps for moving forward.
