Condition & Treatments
/ Low sperm count
Low sperm count: finding the reason, not just the number
A low sperm count (oligozoospermia) means fewer sperm than expected in the semen, usually below 15 million per millilitre. It is one of the most common findings in men trying to conceive, and often has a cause that can be treated.
In studies of men from infertile couples, a low sperm count is one of the most common findings, seen in roughly 1 in 5 to 1 in 3 men [1, 2].
I N S H O R T
A single semen test can be misleading. Results vary, so a low count should always be repeated.
Common causes include varicocele, hormone problems, infection, past testosterone use, genetics and lifestyle.
Treating the cause can raise the count enough to conceive naturally, or improve the chances with IUI or IVF.
Common causes
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Varicocele: swollen veins above the testis.
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Hormone imbalance: low FSH or LH, high prolactin or high oestradiol.
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Testosterone or steroid use, now or in the past.
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Infection or inflammation of the prostate or seminal vesicles.
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Genetic causes, including Y-chromosome deletions, especially when the count is very low.
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Lifestyle and medication: smoking, heavy drinking, excess weight, heat, and some prescribed medicines.
Tests
Repeat semen analysis, ideally in a specialist Andrology lab.
Hormone profile: FSH, LH, testosterone, oestradiol and prolactin.
Scrotal ultrasound, to check for varicocele and other problems in the testes.
Genetic tests, if the count is very low (below 5 million per millilitre).
Semen culture and sperm DNA fragmentation, where relevant
Treatment options
Treatment always starts with finding the cause. Most men need a combination of approaches, and sperm takes around three months to be made, so progress is checked with a repeat semen test about 3 months after each change.
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Varicocele repair. Microsurgical repair of a significant varicocele is one of the most effective treatments for a low count.
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Treating infection. Targeted antibiotics, chosen from semen culture and microbiome results.
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Stopping testosterone or steroids, with treatment to restart sperm production while keeping you well.
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Reviewing medicines. Some prescribed medicines lower sperm production, and can often be changed.
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Tablets that boost the brain's signals, such as clomiphene or enclomiphene, to raise testosterone inside the testes.
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Tablets that lower oestradiol, for men in whom it is high, often with excess weight.
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hCG and FSH injections, which stimulate the testes directly. FSH can improve sperm counts and pregnancy rates in selected men, even when no clear cause is found [3, 4].
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Cabergoline, if prolactin is high
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Weight. Losing excess weight improves hormone balance and sperm quality.
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Smoking, cannabis and alcohol. Stopping smoking and cannabis, and cutting alcohol, all help.
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Heat. Avoiding hot baths, saunas, laptops on the lap and long hours sitting.
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Sleep and exercise. Regular sleep and moderate exercise; very intense training can lower sperm counts.
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Antioxidants may help some men, especially where DNA damage is high, but the evidence is mixed. Prof Raheem recommends only those worth taking, at the right dose and for the right length of time.
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IUI, for milder problems.
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IVF with ICSI, where a single sperm is injected into each egg, for lower counts.
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Freezing several samples in advance, when counts are very low or vary, so enough sperm is ready on egg collection day.
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Testicular sperm for ICSI, when counts are extremely low or DNA damage is high.
Why this matters to your care
A low count is a finding, not a diagnosis. Prof Raheem looks for why it is low before deciding on treatment, so you aren't sent straight to IVF if something simpler could work.
How long until treatment makes a difference?
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Sperm takes around three months to be made, so a new semen test is usually repeated 3 months after starting treatment.
Do supplements work?
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Some antioxidants may help some men. Prof Raheem will tell you which ones are worth taking, and which are not.
Can we still conceive naturally?
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Many couples do, depending on the count, your partner's age and the cause.
Prof Raheem's published work on this topic
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Y-chromosome microdeletions and the sperm count threshold for genetic testing. Link
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BJU International, 2018. Link A review of male infertility. British Journal of Medical and Surgical Urology, 2012. Link
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Male infertility: causes and diagnosis; and Treatment. Trends in Urology and Men's Health, 2011. Link
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Genetic causes of male infertility (book chapter). Link
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Male Infertility in Reproductive Medicine. CRC Press, 2019. Link
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Male infertility (book chapter). Blandy's Urology. Wiley, 2019. Link
References
1. Semen quality of male partners of infertile couples attending a private specialist infertility hospital in Kumasi, Ghana. 2025. Link
2. Abnormalities in semen among male partners of infertile couples, Burdwan Medical College, India. Link
3. Santi D, Granata AR, Simoni M. FSH treatment of male idiopathic infertility improves pregnancy rate: a meta-analysis. Endocrine Connections, 2015;4(3):R46–R58. Link
4. Romeo M, Spaggiari G, Nuzzo F, Granata ARM, Simoni M, Santi D. Follicle stimulating hormone effectiveness in male idiopathic infertility: what happens in daily practice? Andrology, 2022. Link