Male infertility
Medically reviewed by Hormone Journal Editorial Team · Last reviewed 2026-05-22
Male infertility is the inability to cause pregnancy after 12 months of regular unprotected sex, contributing to roughly 50% of all infertility cases worldwide.
What it is
Male infertility is the inability to cause pregnancy in a fertile partner after 12 months of regular, unprotected intercourse, with male factors contributing to approximately 40–50% of all infertility cases globally; men are the sole cause in about 20% of cases and a contributing factor in another 30%. Also called male factor infertility, the condition encompasses any problem with sperm production, sperm function, or sperm transport that reduces a man's capacity to fertilize an egg. In Canada, infertility affects roughly 1 in 6 couples, and fertility investigations are available through provincial health systems, with semen analysis orderable through national laboratory networks such as LifeLabs and Dynacare.
Male infertility is typically a silent condition — most men have no symptoms beyond the inability to achieve pregnancy. This is why semen analysis is the essential first step in any infertility workup, not an afterthought. Importantly, many causes are treatable or can be bypassed with assisted reproductive technology (ART).
Causes and mechanism
Causes fall into four broad categories:
| Category | Examples | Key mechanism |
|---|---|---|
| Hormonal (secondary hypogonadism) | Low FSH/LH, hyperprolactinaemia, thyroid dysfunction, Kallmann syndrome | Reduced hormonal signal to testes impairs testosterone and sperm production |
| Testicular (primary hypogonadism) | Varicocele, Klinefelter syndrome (XXY), cryptorchidism, orchitis, chemotherapy/radiation | Direct damage to sperm-producing tissue |
| Obstructive | Vasectomy, congenital absence of the vas deferens (CFTR mutations), epididymal obstruction | Sperm produced but cannot be delivered |
| Lifestyle and environmental | Anabolic steroid use, obesity, smoking, heat exposure, heavy alcohol use | Suppresses hormonal axis or damages sperm directly |
Varicocele — enlarged scrotal veins that raise testicular temperature — is the most common correctable cause of male infertility. Anabolic steroid use deserves special mention: exogenous testosterone suppresses FSH and LH, shutting down sperm production even while circulating testosterone is high.
Symptoms and diagnosis
Most men with male infertility have no outward signs. Physical findings that may point to an underlying cause include small or soft testes, absent vas deferens on examination, gynecomastia (breast tissue development suggesting hormonal imbalance), reduced facial or body hair, or a palpable varicocele above the testicle.
The standard diagnostic workup proceeds in steps:
- Semen analysis (SA) — the foundation of male fertility evaluation. WHO 2021 reference values: sperm concentration above 16 million/mL, total motility above 42%, normal morphology above 4% by strict (Kruger) criteria. Two separate analyses are recommended before drawing conclusions.
- Hormone panel — FSH, LH, total testosterone, prolactin, TSH, and estradiol. Ordered by a GP or urologist; available through LifeLabs and Dynacare across most provinces.
- Physical examination — by a urologist or andrologist to assess testicular volume and detect varicocele or structural anomalies.
- Scrotal ultrasound — identifies varicocele, testicular masses, or other structural abnormalities.
- Genetic testing — karyotype (for Klinefelter syndrome), Y-chromosome microdeletion analysis, and CFTR mutation testing (for bilateral absence of the vas deferens) in selected cases.
- Testicular biopsy — used in azoospermia (no sperm in ejaculate) to determine whether sperm are being produced but obstructed, or whether production has failed entirely.
Treatment options
Treatment is matched to the identified cause.
Hormonal treatment: Men with secondary hypogonadism (low FSH and LH from pituitary or hypothalamic dysfunction) respond well to gonadotropin therapy — injections of FSH and hCG that stimulate the testes to produce both testosterone and sperm. Hyperprolactinaemia is treated with a dopamine agonist (cabergoline), which often restores normal fertility. Correcting hypothyroidism or hyperthyroidism typically normalizes sperm parameters.
Surgical treatment: Varicocelectomy improves sperm parameters in a meaningful proportion of men and is associated with increased natural conception rates. Vasectomy reversal reconnects the vas deferens. Surgical sperm retrieval — testicular sperm extraction (TESE) or percutaneous epididymal sperm aspiration (PESA) — recovers sperm directly from testicular or epididymal tissue for use in IVF, and is the standard approach in azoospermia.
Assisted reproduction: Intrauterine insemination (IUI) is appropriate for mild male factor infertility. IVF with intracytoplasmic sperm injection (ICSI) — where a single sperm is injected directly into an egg — is the most effective option for severe male factor infertility, including cases where only surgically retrieved sperm are available.
Lifestyle optimization: Stopping anabolic steroids allows the hypothalamic-pituitary-gonadal axis to recover, though this takes approximately 3–6 months. Weight loss, smoking cessation, reducing alcohol intake, and minimizing scrotal heat exposure (laptops, hot baths, tight underwear) are reasonable adjuncts, particularly for men with borderline sperm parameters.
When to see a clinician in Canada
See a physician if you and your partner have been trying to conceive for 12 months without success — or 6 months if your partner is over 35. Seek earlier evaluation if you have a known risk factor: prior varicocele, undescended testes, testicular surgery or trauma, cancer treatment, or a diagnosis of Klinefelter syndrome. Men who have recently stopped anabolic steroids and are concerned about fertility recovery should also seek assessment.
A GP can order the initial semen analysis and hormone panel. Referral to a urologist or reproductive endocrinologist is appropriate if results are abnormal. In Canada, fertility investigations are generally covered under provincial health insurance; ART procedures such as IVF are covered in some provinces (Ontario's OHIP+ program, for example) but not all. Telehealth platforms including Felix, Maple, and Cleo can facilitate initial consultations and referrals for men in areas with limited specialist access.
Limitations and open questions
Research is still emerging on the long-term fertility outcomes of varicocelectomy in men with non-obstructive azoospermia, and evidence on optimal patient selection remains mixed. The clinical significance of borderline sperm morphology — particularly when count and motility are normal — is debated, and different laboratories apply strict Kruger criteria with variable consistency. The role of oxidative stress and sperm DNA fragmentation testing is not yet standardized in Canadian clinical guidelines, and Health Canada has not issued specific guidance on their routine use. For men with idiopathic infertility (no identifiable cause, representing up to 30% of cases), evidence-based treatment options remain limited, and empiric therapies such as antioxidants or clomiphene have shown inconsistent results in randomized trials.
FAQs
Can low testosterone cause male infertility?
Low circulating testosterone does not automatically mean infertility, and the relationship is more nuanced than most people expect. Sperm production is driven primarily by FSH and by testosterone produced locally inside the testes — not by the level measured in a blood test. A man can have low systemic testosterone but still produce sperm. Paradoxically, taking exogenous testosterone (as in testosterone replacement therapy) causes infertility by suppressing FSH and LH, which shuts down sperm production even while blood testosterone is high. Men with secondary hypogonadism (low FSH and LH) can often be successfully treated with gonadotropin injections — FSH and hCG — to stimulate both testosterone and sperm production simultaneously.
Is male infertility permanent?
Not always — the prognosis depends entirely on the underlying cause. Hormonal causes such as secondary hypogonadism and hyperprolactinaemia respond well to targeted medical treatment. Varicocele repair improves sperm parameters in a significant proportion of men. Lifestyle changes — stopping anabolic steroids, losing weight, quitting smoking — can meaningfully improve semen analysis results, though changes take about 3 months to appear (one full sperm development cycle). Even in complete azoospermia, surgical sperm retrieval combined with ICSI-IVF achieves pregnancy for many couples. Irreversible causes, such as severe primary testicular failure from chemotherapy or Klinefelter syndrome, may require donor sperm or adoption, but these represent a minority of cases.
How long does it take for sperm quality to improve after making lifestyle changes?
Sperm take approximately 72 to 90 days to complete their full development cycle (spermatogenesis). This means any positive change — stopping anabolic steroids, losing weight, quitting smoking, correcting a nutritional deficiency — takes roughly 3 months to show up in a semen analysis. Men making lifestyle modifications to improve fertility should wait a full spermatogenic cycle before repeating their semen analysis to get an accurate picture of the impact. Repeating the test too soon will reflect the conditions that existed 2–3 months earlier, not the current state.
Does wearing tight underwear actually affect sperm count?
There is biological plausibility to the concern: optimal sperm production requires a scrotal temperature approximately 2–3°C below core body temperature, which is why the testes are located outside the body. Tight underwear, prolonged sitting, laptops on the lap, and frequent hot baths have all been associated with modestly elevated scrotal temperature in small studies. However, the evidence that these factors cause clinically significant infertility in otherwise healthy men is limited and inconsistent. For men with already borderline sperm parameters, reducing avoidable heat exposure is a reasonable, low-risk precaution — but it is unlikely to be the primary driver of infertility on its own.
Is male infertility investigation covered by provincial health insurance in Canada?
The initial diagnostic workup — semen analysis, hormone blood tests (FSH, LH, testosterone, prolactin, TSH), and a urologist referral — is covered under provincial health insurance in all Canadian provinces when ordered by a physician. Genetic testing (karyotype, Y-chromosome microdeletion, CFTR) is typically covered when there is a clinical indication. Assisted reproductive technologies are a different matter: IVF is publicly funded in Ontario (up to 1 cycle under OHIP), Quebec (tax credit program), and Manitoba, but is not covered in most other provinces. Men should confirm coverage details with their provincial health authority, as policies change.
Sources
- Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline (2021)
- Male Infertility — StatPearls, NCBI Bookshelf (2024)
- Male Infertility: Symptoms and Causes — Mayo Clinic
- Endocrinopathies and Male Infertility — PMC/NIH (2022)
- Genetics of Male Infertility — Nature Reviews Urology (2018)
- Assisted Human Reproduction — Health Canada