Low Sperm Count (Oligozoospermia): What It Means for Fertility
Low sperm count — also known as oligospermia or oligozoospermia — is one of the most common causes of male fertility challenges. But having a lower sperm count doesn’t automatically rule out the chance of pregnancy.
Author
Tassia O’Callaghan
Reviewed by
Kayleigh Hartigan
16 min read
Updated 11th September 2025
Treatment Spotlight:
- Low sperm count (oligozoospermia) means fewer than 15 million sperm per millilitre of semen. [1,2]
- It can affect natural conception — but it doesn’t always mean you can’t get pregnant.
- Causes range from hormonal imbalances and lifestyle factors to genetics or medical conditions. [3,4]
- Treatment options include hormone therapy, surgery, lifestyle changes, and assisted reproduction. [2,3]
- Home sperm tests are available — but a semen analysis through a fertility clinic is more accurate.
What is low sperm count?
Low sperm count (or oligospermia/oligozoospermia) means there are fewer sperm in a person’s semen than expected — specifically, fewer than 15 million sperm per millilitre of semen. If a sperm count is less than 5 million/mL, it’s considered more severe. But if there’s no sperm in semen, it’s known as azoospermia. It’s a common cause of male infertility. [1,2]
Sperm count is just one part of overall sperm health — motility (movement), morphology (shape), and DNA quality also matter when it comes to conception. So a “normal” count doesn’t guarantee fertility, and a low count doesn’t rule it out either.
How common is low sperm count?
Low sperm count is more common than you might think. It’s one of the leading causes of male fertility issues, and it can affect anyone who produces sperm — at any age, and for a range of reasons.
Male factor infertility is involved in around 30-50% of cases where couples are struggling to conceive, as part of a broader picture — and solely responsible in 20% of infertility cases. And low sperm count is one of the most frequently identified issues during semen analysis. [1,2,5]
What are the causes of low sperm count?
There isn’t always a clear answer — and for many, no single cause is ever identified. But we do know that sperm production is sensitive. It relies on a finely balanced system of hormones, genetics, anatomy, and overall health. When any part of that system is disrupted, sperm count can drop.
Here are some of the most common causes:
- Hormone imbalances: Including low testosterone or conditions like hypogonadism, which affect how much of the key fertility hormones your body produces. [1,2]
- Genetic conditions: Such as Klinefelter syndrome, CFTR gene mutations, or Y chromosome microdeletions, which can disrupt normal sperm development. [2]
- Undescended testicles: When testicles didn’t fully descend at birth, even if corrected later, this can still affect fertility later in life. [2]
- Structural issues: Including blockages or damage to the tubes that carry sperm, sometimes due to vasectomy, injury, infection, or congenital absence of the vas deferens. [2]
- Genital infections: Like chlamydia, gonorrhoea, prostatitis, or recurrent urinary tract infections that can interfere with sperm quality or transport. [2]
- Varicoceles: Enlarged veins in the scrotum that may raise testicular temperature and damage sperm production — one of the most common treatable causes. [2]
- Testicular overheating: From frequent sauna use, hot baths, or even prolonged laptop use on the lap, which may impair sperm-making cells. [2]
- Certain medications: Including testosterone replacement therapy, long-term anabolic steroid use, chemotherapy, some antibiotics, and antidepressants. [2]
- Environmental toxins: Exposure to pesticides, industrial chemicals, heavy metals (like lead or cadmium), or pollutants. [2,3]
- Lifestyle factors: Such as smoking, stress, heavy alcohol consumption, cannabis or cocaine use, and exposure to environmental toxins like pesticides or heavy metals. [3,4]
- Weight: Being significantly overweight or underweight can disrupt hormones that regulate sperm production. [3]
Sometimes, no cause is found — this is known as idiopathic oligozoospermia. It doesn’t mean there’s nothing you can do, but it can make decisions around treatment or lifestyle changes more complex. [2]
If a health condition or medication might be affecting your sperm count, it’s important to speak with a doctor before making any changes. And if the reason is unclear, a fertility specialist may recommend further investigations like hormone tests, scrotal ultrasound, or genetic screening to build a fuller picture.
Does low testosterone cause oligospermia?
Yes — testosterone plays a key role in sperm production. If testosterone is too low (hypogonadism), it can result in oligospermia or even azoospermia (no sperm). [6,7]
What are the symptoms of low sperm count?
Low sperm count doesn’t usually cause any noticeable symptoms. Most people only find out through fertility testing, often after trying to conceive for a while without success.
That said, there may be indirect signs — especially if low sperm count is linked to an underlying issue like a hormone imbalance or structural problem. These can include:
- Changes in libido (sex drive), which may point to hormone disruptions
- Difficulty maintaining an erection or other signs of erectile dysfunction
- Pain, swelling or lumps in the testicles or scrotum
- Reduced facial or body hair, which may suggest low testosterone
- Watery or low-volume semen, though this isn’t always linked to sperm count
- Other symptoms of a health condition that can affect sperm production, such as fatigue, weight gain, or mood changes
If you’ve been having regular, unprotected sex for 12 months (or 6 months if your partner is 36 or older) and haven’t conceived, it’s worth speaking to your GP. A semen analysis is the main way to check sperm count — and it’s a straightforward first step in understanding your fertility picture. [3]
Can low sperm count affect fertility?
Yes — it can make it more difficult to conceive, but it doesn’t necessarily mean you can’t.
Sperm count plays an important role in fertility because the fewer sperm there are in each ejaculation, the lower the chance one will reach and fertilise an egg. But it’s just one part of the picture. Sperm also need to move well (motility), have a healthy shape (morphology), and carry stable DNA — all of which influence the chances of conception. [2]
Having a low sperm count doesn’t mean natural conception is off the table. Some people conceive without any medical help, even with levels well below what’s considered ‘normal’. Others may benefit from support, whether that’s making lifestyle changes, exploring treatment options like ICSI, sperm donors, sperm extraction, or checking for underlying health issues that could be affecting sperm production. [8,9,10]
What matters most is getting a clear, informed view of your fertility. A semen analysis is usually the first step — and from there, your GP or fertility specialist can guide the next move based on your individual situation.
Male Fertility Tests & Sperm Tests
Male factor fertility issues play a role in around 50% of couples struggling to conceive — but are often overlooked in the early stages of testing.
How is low sperm count diagnosed?
The most common way to check sperm count is through a semen analysis — a test that looks at how many sperm are in the semen, and also checks their shape, movement, and overall quality. It’s a straightforward process, and your GP can usually arrange it if you’ve been trying to conceive for over a year (or six months if your partner is 36 or older). [3]
You can also choose to book a semen analysis directly through a private fertility clinic — either as a one-off test or as part of a wider fertility assessment. This can be a helpful option if you’d prefer not to wait or want a more detailed picture sooner.
Because sperm levels can naturally fluctuate, you’ll usually be asked to do a second test after around 12 weeks to confirm the results. [11]
If both tests show a low count, a fertility specialist may recommend further investigations, such as:
- Hormone blood tests: To check for imbalances that might be affecting sperm production.
- Scrotal ultrasound: To assess for physical issues like varicoceles (enlarged veins) or signs of injury or obstruction.
- Genetic screening: Particularly if the sperm count is very low or zero, to look for inherited conditions.
- Urine tests after ejaculation: To check for retrograde ejaculation (when semen flows backwards into the bladder).
These next steps help identify whether the cause is treatable, whether assisted conception (like IVF or ICSI) might be needed, or whether lifestyle changes could help improve things.
If you’re considering a private test, Fertility Mapper can help you compare clinics and find the right one for your needs. Our Clinic Match tool makes it easier to see which clinics offer sperm testing, what they specialise in, and whether they align with your priorities — whether that’s budget, wait times, or how supported you’ll feel.
How to check sperm count at home
At-home sperm tests are available and can be a helpful starting point if you’re curious about your sperm health. They’re discreet, usually involve collecting a semen sample and using a device or app to analyse it, and can give you a general indication of whether sperm are present.
But there’s a key detail to understand: most home tests are qualitative, not quantitative. That means they can often tell you if sperm are there — but not how many, how well they move, or what they look like. And those are crucial pieces of the fertility puzzle.
Some more advanced kits may estimate sperm concentration, but results can still vary depending on how the sample was collected, how long it took to process, and how the test interprets the data.
If you’re using an at-home sperm test, we recommend following it up with a consultation from a medical professional — ideally a fertility specialist. This helps put the results into context and can highlight if further testing is needed. Alternatively, you can skip the guesswork and go straight to a clinic for a semen analysis, which will give you a much clearer picture.
If you’re unsure where to start, we at Fertility Mapper can help you find a trusted fertility clinic offering semen analysis with our Clinic Match tool.
How much does a sperm count test cost?
If you’re eligible for a semen analysis through your GP, a sperm motility test will usually be free of charge.
For private testing, costs vary by clinic and by how detailed the assessment is. A basic semen analysis in a fertility clinic typically ranges from £100-£210, with an average of £175. Some clinics also offer broader packages that include advanced testing, consultations, and fertility coaching. For example, the advertised cost of a Fertility MOT for a heterosexual couple before treatment can range from £449-£1,150, with a median of £475.
You can also book semen analysis directly through andrology centres and clinics. From the sample we’ve reviewed across the UK, costs sit between £139-£199, with a median of £189.
Home tests for semen analysis are available too, priced between £84.99-£320 (median £98). While these can provide initial insights, we recommend testing with a medical professional, as this gives you access to expert interpretation and tailored advice alongside the results.
We’re continuing to gather cost data across the UK and will update this section with more detailed comparisons soon.
Can you treat low sperm count?
Yes — there are ways to move forward with a low sperm count, and having fewer sperm doesn’t always mean your chances of parenthood are out of reach. What treatment looks like depends on the cause, how low the count is, and what the rest of your fertility picture looks like (including your partner’s, if you have one).
What is the best treatment for oligospermia?
The most effective treatment for low sperm count is often considered to be intracytoplasmic sperm injection (ICSI). It’s a type of IVF where a single sperm is injected directly into an egg in a lab — bypassing many of the barriers that sperm might otherwise face. It’s widely used and has become the standard recommendation for:
- Very low sperm count
- Poor sperm motility (movement) or morphology (shape)
- Cases where sperm has been surgically retrieved
- Previous IVF cycles where fertilisation didn’t happen
ICSI can be used even when sperm numbers are extremely low, as only one good-quality sperm is needed per egg. But it’s not always the right fit — especially if issues with egg quality are also involved. [8]
Other treatments for low sperm count
While ICSI is often the go-to fertility treatment for very low sperm count, it’s not the only option. Depending on your individual diagnosis, medical history, and personal preferences, your clinic might explore other routes — either instead of, or alongside, ICSI.
Here are some of the other treatments that may be offered:
- Surgical sperm extraction: If no sperm are found in the semen (azoospermia), or the count is extremely low, sperm can sometimes be retrieved directly from the testicles or epididymis. There are several methods — including percutaneous epididymal sperm aspiration (PESA), microsurgical epididymal sperm aspiration (MESA), testicular sperm aspiration (TESA), testicular sperm extraction (TESE, single or multi-site), and microscope-assisted testicular sperm extraction (MicroTESE) — and the right one depends on whether the issue is a blockage or a problem with sperm production. [9]
- IVF (in vitro fertilisation): In some cases, if sperm quality is borderline or the issue is unexplained, IVF without ICSI may be used — particularly if motility and morphology are still within a reasonable range. This involves combining sperm and eggs in a lab to encourage natural fertilisation. [12]
- Donor sperm: If no usable sperm can be found or retrieved — or if treatment with your own sperm isn’t recommended — you might consider using donor sperm. This can be a powerful option, whether you’re trying to conceive via IVF, IUI, or home insemination (though the latter is not recommended outside a licensed clinic due to safety and legal implications). [10]
- Lifestyle changes and supplements: In mild or borderline cases, your doctor might recommend lifestyle interventions to support sperm production. These could include stopping smoking, reducing alcohol or drug use, maintaining a moderate weight, improving sleep, and avoiding heat or chemical exposure. Some supplements (like CoQ10, zinc, or antioxidants) are also sometimes suggested, though evidence on their effectiveness is still evolving. [2,3]
Find the right clinic for you
Choosing a clinic is one of the biggest decisions you’ll make. We’ll help find the best options for you, whatever your journey.
How does low sperm count affect fertility treatment?
Low sperm count can influence the kind of fertility treatment you’re offered — and how likely it is to work. But it doesn’t mean treatment won’t work at all. Depending on your sperm count (and other factors like motility and morphology), your clinic may suggest different options — from timed sex or IUI, through to IVF or ICSI. Here’s what low sperm count means for each treatment
- Intrauterine insemination (IUI): IUI places sperm directly into the uterus to help them reach the egg more easily. It’s a common first-line treatment for mild male factor infertility — but success depends heavily on sperm count and quality. If your post-wash progressive sperm count is under 5 million, IUI is very unlikely to work. With counts above 5 million, pregnancy rates range from 11%–14% per cycle. Most successful IUI pregnancies happen within the first three attempts — after that, IVF is usually recommended. [13,14]
- In vitro fertilisation (IVF): IVF can work for people with low sperm count — but the success rate may still be affected, especially at lower ranges. If your total motile sperm count (TMSC) is below around 10 million, success with standard IVF may drop. Some clinics may recommend going straight to ICSI if sperm count or motility is particularly low. [15]
- Intracytoplasmic sperm injection (ICSI): ICSI is often the most successful treatment option for low sperm count. It’s suitable even for severe male factor infertility (TMSC <5 million or even <1 million). [8]
- Sperm freezing and fertility preservation: If you’ve been diagnosed with a low sperm count, freezing sperm early could preserve your current fertility for future treatment. Freezing may be particularly useful if your sperm count is declining or you’re about to start treatment that could affect fertility. Not all sperm survive the freeze-thaw process, so your clinic will assess sperm quality before storage. [16,17]
What is the minimum sperm count for IVF?
There’s no single number that defines a universal “minimum sperm count” for IVF — it can vary depending on the fertility clinic, the specific approach they use, and the individual circumstances of both partners. But in general, most clinics require at least 50,000 to 500,000 motile sperm per egg to attempt conventional IVF (where sperm and egg are mixed in a dish to fertilise naturally in the lab). [2]
That said, when total motile sperm count (TMSC) drops below about 5 million, many clinics may recommend ICSI (intracytoplasmic sperm injection) IVF instead. This is a more targeted version of IVF where a single sperm is injected directly into the egg — and it’s often used when sperm count, motility or morphology is significantly reduced. [2]
Some clinics may still consider conventional IVF if the sperm meet certain quality thresholds, even with a lower count — but others might have stricter criteria, especially if previous attempts haven’t resulted in fertilisation.
Can you still get pregnant with a low sperm count?
Yes — it is possible to get pregnant with a low sperm count.
A low sperm count can make conception more difficult, but it doesn’t make it impossible. Some people with low sperm counts do conceive naturally, particularly if the sperm that are present are healthy in other ways (like having good motility and morphology). Others may benefit from fertility treatment — including options like IUI, IVF, or ICSI — depending on their specific test results and their partner’s fertility profile too.
What’s important to know is:
- Low sperm count is just one piece of the fertility picture.
- Treatment can help — and even severe cases of low count can be managed with techniques like ICSI.
- Lifestyle changes (such as reducing alcohol, stopping smoking, managing weight, and avoiding harmful chemicals or heat to the testicles) can make a meaningful difference for some people.
- A fertility specialist can guide you through personalised testing and treatment options, including whether donor sperm might be worth exploring.
If you’ve been trying to conceive for over a year (or six months if your partner is 36 or older), it’s a good idea to speak to your GP. You can also explore fertility clinics directly if you’re ready to investigate further — our Clinic Match tool can help you find clinics that support male factor fertility.
You’re not alone in this — and with the right information and support, you can make empowered choices about next steps.
Sources
1. NHS 111 Wales. Low sperm count (oligozoospermia). Last Updated: 18/10/2023.
2. Leslie SW, Soon-Sutton TL, Khan MAB. Male Infertility. Updated 2024 Feb 25.
3. NHS. Low sperm count. Page last reviewed: 26 January 2024.
4. Ilacqua A, Izzo G, Emerenziani GP, Baldari C, Aversa A. Lifestyle and fertility: the influence of stress and quality of life on male fertility. Reprod Biol Endocrinol. 2018 Nov 26;16(1):115. doi: 10.1186/s12958-018-0436-9. PMID: 30474562; PMCID: PMC6260894.
5. Human Fertilisation & Embryology Authority. Male infertility: “It’s not just about having a few extra tests. It’s about the right emotional and medical support.”
6. Di Guardo F, Vloeberghs V, Bardhi E, Blockeel C, Verheyen G, Tournaye H, Drakopoulos P. Low Testosterone and Semen Parameters in Male Partners of Infertile Couples Undergoing IVF with a Total Sperm Count Greater than 5 Million. J Clin Med. 2020 Nov 26;9(12):3824. doi: 10.3390/jcm9123824. PMID: 33255908; PMCID: PMC7761260.
7. NHS. The ‘male menopause’. Page last reviewed: 13 October 2022.
8. Human Fertilisation & Embryology Authority. Intracytoplasmic sperm injection (ICSI).
9. Human Fertilisation & Embryology Authority. Surgical sperm extraction
10. Human Fertilisation & Embryology Authority. Home insemination with donor sperm.
11. Acorn Andrology website.
12. Human Fertilisation & Embryology Authority. In vitro fertilisation (IVF).
13. Zhang E, Tao X, Xing W, Cai L, Zhang B. Effect of sperm count on success of intrauterine insemination in couples diagnosed with male factor infertility. Mater Sociomed. 2014 Oct;26(5):321-3. doi: 10.5455/msm.2014.26.321-323. Epub 2014 Oct 29. PMID: 25568631; PMCID: PMC4272842.
14. Human Fertilisation & Embryology Authority. Intrauterine insemination (IUI).
15. Van Voorhis, B.J., Barnett, M., Sparks, A.E., Syrop, C.H., Rosenthal, G. and Dawson, J., 2001. Effect of the total motile sperm count on the efficacy and cost-effectiveness of intrauterine insemination and in vitro fertilization. Fertility and sterility, 75(4), pp.661-668.
16. NHS Guy’s and St Thomas’, NHS Foundation Trust. Fertility preservation for men. Last reviewed: July 2024.
17. Human Fertilisation & Embryology Authority. Sperm freezing.