The international definition of infertility is failure to achieve a clinical pregnancy after 12 months or more of regular, unprotected sex.1 Male infertility is the part of that picture that comes from the man: low sperm numbers, poor movement or shape, blockages, hormone problems or difficulties with erection and ejaculation.
It is common and under-discussed. Infertility affects an estimated 15% of couples worldwide; a male factor is solely responsible in around 20 to 30% of cases and contributes to about half overall.2
It is also a health signal. The EAU guideline notes that infertile men are at higher risk of other conditions, including cardiovascular disease and cancer, and should be assessed and counselled with that in mind.3
What causes male infertility?
The main causes are problems with sperm production, blockages in the ducts that carry sperm, hormone problems and difficulties with erection or ejaculation. In many men, no specific cause is found.
Testosterone deserves a special mention. Taking it, whether prescribed or bought for the gym, suppresses the hormones that drive sperm production, which is why the Endocrine Society recommends against starting testosterone in men planning fertility in the near term.4
- Sperm production: low count, poor motility or morphology, or no sperm at all (azoospermia)
- Structural: varicocele, blockages in the epididymis or vas deferens, previous surgery
- Hormonal: hypogonadism, raised prolactin, testosterone or steroid use
- Sexual function: erectile dysfunction, retrograde ejaculation, delayed ejaculation
- Genetic: chromosomal conditions such as Klinefelter syndrome
How is male infertility diagnosed?
It starts with a medical history, a physical examination and a semen analysis. Depending on the results, hormone tests, an ultrasound and genetic tests may follow.
The EAU guideline recommends that the male partner in every infertile couple has a comprehensive urological assessment to identify and treat modifiable risk factors.3 In practice, that means someone should examine you, not just read a lab report.
A semen analysis is compared against WHO reference values, and one abnormal result is usually repeated, because counts vary from sample to sample. Hormone tests such as testosterone, FSH and LH help show whether a problem lies in the testes or in the signals from the brain.
Can male infertility be treated?
Often, at least in part. Some causes can be directly fixed; for others, assisted reproduction such as IVF with ICSI can work with very few sperm.
Potentially fixable causes include testosterone or steroid use, hormone deficiencies, some blockages and erection or ejaculation problems. Varicocele repair may help some couples, though the evidence on live births is uncertain.
If you are considering supplements, it helps to talk them through with your doctor alongside other investigations. The EAU guideline does not make a recommendation for widespread use of empirical treatments such as antioxidants, and notes that many treatments in routine use have yet to be tested in high-quality trials.3 Our look at guide to supplement ingredients and the research goes into detail, and lifestyle factors that affect male fertility covers what is in your control.
When should a man get checked?
Once a couple has been trying for 12 months without a pregnancy, both partners should be assessed at the same time.1 Go sooner if you know of a risk factor.
Risk factors worth acting on early include undescended testes, previous testicular surgery or injury, cancer treatment, a known varicocele, low libido or erection problems, and any testosterone or steroid use. A semen analysis is simple and non-invasive, so there is little reason to leave it until last.
Fertility trouble can land heavily on a man's sense of himself. That reaction is normal, and it is worth talking about with your partner and, if it helps, a counsellor.
Common questions
How common is male infertility?
Very. Infertility affects roughly 15% of couples, and a male factor is involved in about half of cases, either alone or alongside a female factor.2
Can a man be infertile and still have normal erections and ejaculation?
Yes. Sex drive, erections and semen volume can all be completely normal while sperm count or quality is low. Only a semen analysis shows what is happening at the sperm level.
Is male infertility linked to other health problems?
It can be a marker. Infertile men have a higher risk of cardiovascular disease and some cancers, so a full medical assessment is worthwhile even if a couple moves straight to IVF.3
Read more on this
Lifestyle factors that affect male fertility: a practical guide
Supplement ingredients for men’s sexual health: what the research shows
How long does it take sperm to regenerate?
Sources
- Zegers-Hochschild F, Adamson GD, Dyer S, et al. The International Glossary on Infertility and Fertility Care, 2017. Fertil Steril. 2017;108(3):393-406. PubMed
- Agarwal A, Mulgund A, Hamada A, Chyatte MR. A unique view on male infertility around the globe. Reprod Biol Endocrinol. 2015;13:37. PubMed
- Minhas S, Bettocchi C, Boeri L, et al. European Association of Urology Guidelines on Male Sexual and Reproductive Health: 2021 Update on Male Infertility. Eur Urol. 2021;80(5):603-620. PubMed
- Bhasin S, Brito JP, Cunningham GR, et al. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. PubMed
Not medical advice. Written by Eric Stephens from the research cited above; not reviewed by a doctor. If something worries you, see a GP.