A low sperm count means there are fewer sperm than normal in a semen sample, and it is one of the most common reasons couples struggle to conceive naturally. It does not mean pregnancy is impossible, but it usually means the path to parenthood needs a bit more patience, testing, or medical support.
Doctors describe a low sperm count, also called oligospermia, as a concentration below 15 million sperm per millilitre of semen. Anything above that figure is generally considered within a fertile range, although sperm quality involves far more than count alone. Movement, shape, and volume all play a part in whether sperm can reach and fertilise an egg.
What Counts as a Low Sperm Count?
A semen analysis is the only reliable way to confirm a low sperm count. The test looks at three main measurements: how many sperm are present, how well they move, and how normally they are shaped. A result under 15 million per millilitre is classed as low, while a count under 5 million is described as severe.
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It is worth remembering that one abnormal result does not always confirm the problem. Sperm production naturally varies, so a repeat test around three months later is standard practice before any diagnosis is finalised. Our guide to reading a sperm count result walks through what each figure on the report actually means.
What Causes a Low Sperm Count?
There is rarely a single explanation for a low sperm count, and the causes generally fall into three categories: medical, environmental, and lifestyle related. Understanding which category applies can help guide the right next step.
Medical causes include hormone imbalances such as low testosterone, a swollen vein in the scrotum known as a varicocele, previous infections, blockages in the tubes that carry sperm, and genetic conditions including Klinefelter syndrome. Structural issues, such as undescended testicles or previous surgery, can also reduce the number of sperm produced.
Environmental exposure plays a bigger role than many people realise. Heat is one of the clearest culprits, since the testicles need to stay slightly cooler than the rest of the body to produce healthy sperm. Frequent hot baths, saunas, or tight underwear can all raise the temperature enough to affect production. Exposure to pesticides, solvents, and certain heavy metals at work has also been linked to reduced sperm production over time.
Lifestyle factors are often the most within a person’s control. Smoking, heavy alcohol use, obesity, recreational drug use, and anabolic steroids have all been associated with reduced sperm concentration. Poor sleep and a diet lacking in key nutrients can also play a supporting role, even if they are rarely the sole cause.
Can Stress Cause a Low Sperm Count?
Yes, stress can contribute to a low sperm count, although it is rarely the only factor at play. A widely cited study from Columbia University’s Mailman School of Public Health and Rutgers School of Public Health found that men reporting higher life stress had measurably lower sperm concentration, along with more abnormally shaped and less mobile sperm.
The exact mechanism is still being studied, but researchers believe stress hormones called glucocorticoids may interfere with testosterone production, which in turn affects how much sperm the body makes. Oxidative stress inside the body is another suspected pathway, since it is known to damage sperm cells directly.
There is an emotional side to this too. Many men feel a quiet pressure around fertility that they are reluctant to discuss, even with a partner or a doctor. That reluctance can delay diagnosis and treatment, which only prolongs the stress of not knowing. Recognising it as a medical issue, not a reflection of masculinity, is often the first step towards addressing it.
How Common Is Male Infertility?
Male factors are involved in around 40 to 50% of all cases where a couple struggles to conceive, either alone or alongside a female factor. A low sperm count is one of the leading contributors, but it sits alongside issues such as poor motility, abnormal shape, or blockages that prevent sperm from being ejaculated at all.
| Category | Common Examples | Often Reversible? |
|---|---|---|
| Medical | Varicocele, hormone imbalance, infection, genetic conditions | Sometimes, with treatment |
| Environmental | Heat exposure, pesticides, solvents, heavy metals | Usually, once removed |
| Lifestyle | Smoking, alcohol, obesity, steroid use, poor sleep | Often, with changes over time |
How Is a Low Sperm Count Diagnosed?
The first step is a semen analysis, usually requested by a GP after a couple has been trying to conceive for over a year without success, or six months if the female partner is over 35, according to the NHS. If the first test shows a low result, a second sample is normally tested a few months later to confirm the finding, since results can vary naturally between samples.
If it is confirmed, further tests may follow, including blood tests to check hormone levels, an ultrasound scan of the testicles, or a urine test to rule out infection. In some cases, a referral to a specialist andrologist or urologist is recommended, particularly where a genetic cause is suspected.
How to Improve a Low Sperm Count Naturally
Many men can improve a low sperm count through changes that take a few months to show results, since sperm takes around 70 to 90 days to fully develop. The NHS recommends several practical steps for anyone in this situation who wants to improve their chances of conceiving naturally.
Cutting back on alcohol to within the recommended 14 units a week, stopping smoking, and losing weight if overweight are among the most consistently supported changes. Wearing looser underwear, avoiding prolonged heat exposure, and limiting contact with workplace chemicals such as pesticides or solvents can also help protect sperm production. Regular, moderate exercise and a diet rich in fruit, vegetables, and healthy fats support overall hormone balance, which indirectly supports sperm health.
Managing stress deserves equal attention. A 2014 study from Columbia University found that reducing life stress was linked to healthier semen quality, so simple habits such as regular exercise, better sleep routines, and talking openly about fertility concerns, whether with a partner, a GP, or a counsellor, can reduce the psychological weight that so often accompanies a low sperm count diagnosis.
Treatment Options for Low Sperm Count
If lifestyle changes alone are not enough, medical treatment may be recommended. Depending on the cause, this can include surgery to correct a varicocele, hormone therapy to address an imbalance, or antibiotics where an infection is responsible.
Where natural conception remains difficult after a year of trying, fertility treatments such as intrauterine insemination, in vitro fertilisation, or intracytoplasmic sperm injection (ICSI) can significantly improve the odds. ICSI, in particular, is often recommended specifically for a low sperm count, since it only requires a single healthy sperm to fertilise each egg. In severe cases, or where sperm cannot be retrieved at all, using a donor is sometimes the most realistic route to parenthood, and many people explore known donor arrangements as a more personal and often more affordable alternative to a clinic-only pathway.
Comparing the realistic cost of fertility treatment before committing to a clinic can help set expectations early, and understanding your local NHS funding rules is equally worthwhile, since eligibility varies by postcode. Anyone considering a known donor route may also want to read up on the legal side of donor conception in the UK before starting conversations with a potential donor.
Frequently Asked Questions
Can you still get pregnant with a low sperm count?
Yes. A low sperm count reduces the odds per cycle but does not rule out natural conception, and many couples succeed with patience, timing, and healthy lifestyle changes.
Is a low sperm count permanent?
Not always. Where the cause is lifestyle or environmental, a low sperm count often improves within a few months of changing habits, since new sperm takes around three months to mature.
What foods help with a low sperm count?
A diet rich in antioxidants, such as fruit, vegetables, nuts, and oily fish, supports healthy sperm production, alongside cutting back on processed food and alcohol.
Should I see a doctor about a low sperm count?
Yes, especially after a year of trying to conceive without success, or sooner if there are other symptoms such as testicular pain, swelling, or a history of infection or surgery.
Does age affect a low sperm count?
Sperm quality can decline gradually with age, though the effect is far less dramatic than the decline in female fertility, and low counts can occur at any age.
Whatever the cause, a low sperm count is rarely the end of the story. Many people trying to conceive, whether with a partner, a known donor, or through a clinic, go on to become parents once the right combination of lifestyle changes, treatment, or support is in place. Tracking your fertile window with a good fertility app can also make the most of the sperm you do have, whatever your results show.
If you are exploring known donor conception or looking to connect with others on the same path, CoParents.co.uk brings together people across the UK navigating fertility challenges, sperm donation, and co-parenting. Joining a community built around honest, supportive conversations can make the journey feel a little less isolating, whether you are looking for a sperm donor or want to find a co-parent to start a family with. Register free on CoParents.co.uk to start exploring your options today.