What can a sperm test reveal about your fertility?

When a couple struggles to conceive, most people assume the problem lies with her. In roughly half of cases, he’s part of it too [1].

But often, there are no warning signs or symptoms. You can be fit and healthy, yet still have sperm that aren’t moving, swimming in the wrong direction, or even missing tails.

A sperm test (semen analysis) is how you find out. But it’s not a simple pass or fail; there are quite a few aspects to look at. And even a normal result doesn’t guarantee you can have kids.

Here’s what it can and can’t tell you, and what to do if your numbers aren’t quite what you hoped.

In this blog, we cover:

• What is a sperm test?
• What does a sperm test measure?
• Can a sperm test tell if I’m fertile?
• What can affect my results?
• What happens if my results are abnormal?
• When should I consider taking a test?
• Can I take a sperm test at home?
   

What is a sperm test?

A sperm test, or semen analysis, is a lab check of a semen sample. It’s a way of finding out how your sperm are doing and it’s usually one of the first tests offered to a man if he’s having fertility problems.

A sperm test looks at:

• Concentration - how many sperm you have
• Motility - how well they move
• Morphology - their shape
• Volume - how much semen you produce

Each of these affects how likely sperm are to reach and fertilise an egg.

It’s worth remembering though, a sperm test can’t give you a definitive yes-or-no answer about your fertility. Think of it as a useful starting point for understanding your reproductive health.
 

What does a sperm test measure?

Having plenty of sperm isn’t enough on its own. They also need to swim in the right direction and be the right shape to fertilise an egg. A semen analysis checks a few different parameters.

A note on what's ‘normal’: Reference values are based on men who successfully conceived with their partners. But 5% of those men had results below these values, which shows that you can still be fertile even if your results fall outside the reference range.

Sperm concentration: how many are there?

It only takes one sperm to fertilise an egg. Tens of millions are released in a single ejaculation but most of them never get anywhere near the egg.

Your report shows this in two ways: concentration (number of sperm/mL) and total sperm number (number of sperm in the whole sample). It also gives your motile sperm concentration, the number of moving sperm per millilitre.

A low count can make conception less likely, but it doesn’t mean you can’t get someone pregnant.

Sperm motility: are they good swimmers?

To reach the egg, sperm cells have to travel through the cervix, the uterus, and the fallopian tubes. Some are much better at this than others.

Motility describes how well your sperm move.

The lab sorts motility into three groups:

• Progressive – swimming forwards with purpose
• Non-progressive – moving, but not getting anywhere
• Immotile – not moving at all

Not all sperm are progressive, and that’s OK.

Sperm morphology: are they the right shape?

Picture a tadpole with an oval head and long tail. That’s roughly what a healthy sperm looks like.

Morphology is all about shape and structure. Under the microscope, the lab checks the head, the midpiece (the section that powers the tail), and the tail itself.

Surprisingly, most sperm in a normal sample look abnormal.

Semen volume: how much is there?

Semen and sperm aren’t the same thing. Sperm are the cells, whereas semen is the fluid that carries them.

A very low volume can point to a problem with semen production, ejaculation, or a blockage in the reproductive tract. It can also mean some of the sample was missed during collection.

What else is on my report?

Your report also looks at the sample itself, including its colour, how long it takes to liquefy, and how thick it is. Delayed liquefaction or high thickness (viscosity) can make it harder for sperm to move.

It also checks whether sperm are clumping together and counts round cells. Round cells include immature sperm and white blood cells. Higher numbers sometimes warrant further tests.
 

Can a sperm test tell if I’m fertile?

No, not on its own. A semen analysis tells you a lot about your sperm, but fertility is bigger than that. It also depends on your partner, timing, and on things a standard test doesn’t measure.

So, you can have a perfectly normal result and still struggle to conceive. On the other hand, men with low counts or poor motility may also conceive without problems [3].

It’s also worth remembering that sperm quality can fluctuate. Illness, lifestyle factors, and even how recently you last ejaculated can affect your results.
 

What can affect my sperm test results?

A poor result doesn’t always point to a lasting problem. Sometimes, the cause is temporary, and sometimes it’s the sample itself.

Sperm take around three months to develop, so your results reflect the last few months of your health, not just today. The flip side is that any change you make now will take a few months to show up in a retest.

Lifestyle factors

• Smoking and recreational drugs: Cigarette smoke contains chemicals that damage sperm and may lower count and motility [4]. Cannabis and other recreational drugs are linked to poorer sperm quality too.
• Alcohol: Regular heavy drinking can disrupt hormone production and sperm quality [5].
• Weight: Excess body fat can affect reproductive hormones and is associated with poorer sperm quality [6].

General health and medications

• Recent illness: A fever can temporarily reduce sperm production [7].
• Testosterone and anabolic steroids: These are often overlooked. Taking testosterone, whether prescribed as TRT or used for bodybuilding, can reduce sperm production to very low levels, or even zero [8]. In many men, it recovers after stopping, but it can take months, sometimes longer. Always discuss with your testosterone prescriber before stopping.
• Medical conditions: Varicocoeles (enlarged veins around the testicles), hormone disorders, infections, and an undescended testicle in childhood can all affect sperm production [9,10].

Sample collection

Timing matters too. The usual guidance is to go two to seven days without ejaculating before you collect your sample. Recent ejaculation can lower volume and count, while waiting much longer than a week may reduce motility. Missing part of the sample can also skew the result, so be sure to follow the instructions closely.

Many of these causes are reversible, but a semen analysis can’t tell you which one is behind your result. If your numbers aren’t what you hoped, here’s what to do next.

Find out more about factors affecting male fertility in our blog.
 

What happens if my results are abnormal?

An abnormal result can be unsettling, but it doesn’t necessarily mean you’re infertile. Sperm quality fluctuates, so the first step is usually to repeat the test.

That’s typically done around three months later, giving your body time to produce new sperm [11]. It’s also when any changes you’ve made, like stopping smoking, are likely to show up. If your count is very low, or no sperm were found, don’t wait. That needs to be followed up sooner.

If the repeat is still abnormal

See your GP. They may recommend further assessment, such as:

• A physical examination – to check for problems like a varicocoele (enlarged veins around the testicles)
• Hormone blood tests - testosterone, follicle-stimulating hormone (FSH), and luteinising hormone (LH) help show whether the issue lies in the testicles or in the signals from the brain
• Further tests – such as a scrotal ultrasound, or genetic tests
• A specialist referral – a urology or fertility clinic referral may be the next step

Even if these are abnormal, it’s still not the end of the road

If lifestyle changes or treating an underlying condition don’t improve your results, there may still be options. In-vitro fertilisation (IVF) with intracytoplasmic sperm injection (ICSI), for example, injects a single sperm directly into an egg, so it can work even when counts are very low.

Fertility depends on both of you. If you’ve been trying for a year without success, see your GP together.
 

When should I consider taking a sperm test?

You don’t have to wait until you’re struggling to conceive. Testing before you start trying can flag a problem early.

Consider a sperm test if:

• You’ve been trying for a while without success. Namely, if you’ve had regular, unprotected sex for 12 months without conceiving. Don’t wait that long if your partner is 36 or over, or if either of you has a known fertility condition [11].
• You’re planning a family, or you’re just curious. This is a personal choice, but some men like to know where they stand.
• You have a history of testicular problems. Undescended testicles, injuries, infections like mumps, and varicocoeles can all affect sperm production.
• You’re taking, or have had, treatment that can affect fertility. That includes chemotherapy, radiotherapy, testosterone replacement therapy (TRT), and anabolic steroids.
   

Can I take a sperm test at home?

Yes, and thankfully, that means there’s no awkward trip to a fertility clinic.

With the Male Fertility Sperm Test, developed in partnership with Malebox, you can collect your sample in the privacy of your own home. Unlike basic home sperm-count kits, which may only measure a couple of aspects of sperm health, this is a full semen analysis. It also includes a testosterone blood test, which matters for sperm production.

How does an at-home sperm test work?

It’s fairly straightforward. You’ll receive a test kit with everything you need. You’ll need to avoid ejaculating for two to seven days beforehand [2], then collect your sample in the pot. Follow the instructions carefully. How you collect and store your sample can affect your results.

You send off the sample by post to the laboratory where it’s analysed. Results are usually available within two days of the lab receiving the sample. You’ll then receive your results through your secure online dashboard.

How accurate are at-home sperm tests?

Semen analysis varies naturally, even in a clinic. Results differ between samples, and between technicians reading the same one. The WHO manual sets limits on how far repeat readings of one sample can differ. This is known as repeatability, or precision.

Malebox, which runs the analysis, has validated the test by comparing home-kit results with fresh samples in clinic. A preservative helps keep the sample from degrading, and a predictive model adjusts for time in the post [12].

You therefore end up with data comparable to that at a clinic, without the stress of going in.
 

Sperm health is worth knowing about

There's a lot you can't tell about your fertility just by how you look or feel. A semen analysis gives you a closer look at what's happening, and may help explain why conception isn't happening as expected.

It won't give you all the answers, but it can tell you whether there's something worth investigating further.

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References

1. Eisenberg ML, Esteves SC, Lamb DJ, Hotaling JM, Giwercman A, Hwang K, et al. Male infertility. Nat Rev Dis Primer. 2023;9: 49. doi:10.1038/s41572-023-00459-w
2. World Health Organization. WHO laboratory manual for the examination and processing of human semen. Geneva: WHO; 2021. Available: https://www.who.int/publications/i/item/9789240030787
3. Schlegel PN, Sigman M, Collura B, De Jonge CJ, Eisenberg ML, Lamb DJ, et al. Diagnosis and treatment of infertility in men: AUA/ASRM guideline part I. Fertil Steril. 2021;115: 54–61. doi:10.1016/j.fertnstert.2020.11.015
4. Bundhun PK, Janoo G, Bhurtu A, Teeluck AR, Soogund MZS, Pursun M, et al. Tobacco smoking and semen quality in infertile males: a systematic review and meta-analysis. BMC Public Health. 2019;19: 36. doi:10.1186/s12889-018-6319-3
5. Finelli R, Mottola F, Agarwal A. Impact of Alcohol Consumption on Male Fertility Potential: A Narrative Review. Int J Environ Res Public Health. 2021;19: 328. doi:10.3390/ijerph19010328
6. Ma D, Zhang M, Zhang X, Xu L. Beyond body mass index: the role of fat distribution in male sperm quality. Front Endocrinol. 2025;16: 1702791. doi:10.3389/fendo.2025.1702791
7. Carlsen E, Andersson A-M, Petersen JH, Skakkebaek NE. History of febrile illness and variation in semen quality. Hum Reprod. 2003;18: 2089–2092. doi:10.1093/humrep/deg412
8. Schlegel P, Sigman M, Collura B, De Jonge C, Eisenberg M, Lamb D. Diagnosis and treatment of infertility in men: AUA/ASRM guideline part II. Fertil Steril. 2021;115: 62–69. doi:10.1016/j.fertnstert.2020.11.016
9. Kantartzi PD, Goulis CD, Goulis GD, Papadimas I. Male infertility and varicocele: myths and reality. Hippokratia. 2007;11: 99–104.
10. Goel P, Rawat JD, Wakhlu A, Kureel SN. Undescended testicle: An update on fertility in cryptorchid men. Indian J Med Res. 2015;141: 163–171. doi:10.4103/0971-5916.155544
11. National Institute for Health and Care Excellence. NICE guideline NG257. Fertility problems: assessment and treatment. NICE; 2026. Available: https://www.nice.org.uk/guidance/ng257
12. Are Home Sperm Test Kits Accurate? Here’s What To Know. In: Malebox Health [Internet]. 2 June 2026 [cited 11 Oct 2026]. Available: https://maleboxhealth.com/blogs/post/are-home-sperm-test-kits-accurate