Low Sperm Count: Causes, Treatment & Pregnancy Chances

Quick answer

A low sperm count, known medically as oligospermia, means there are fewer than 16 million sperm per millilitre of semen, based on the WHO 2021 reference values. It is one of the most common causes of male infertility, yet it rarely means pregnancy is impossible. Most men with a low count still have some healthy, moving sperm, and many go on to conceive naturally or with help such as lifestyle changes, treating an underlying cause, IUI, or IVF with ICSI. A simple semen analysis is the first step to knowing where you stand.

Key facts at a glance

Definition: a sperm concentration below 16 million per millilitre, according to the WHO 2021 reference values.

How common: male factors contribute to roughly 40 to 50 percent of all infertility cases.

How it is found: through a semen analysis, usually repeated once to confirm the result.

Severity: it ranges from mild to moderate to severe oligospermia, or azoospermia, which means no sperm at all.

Reversible causes: heat, smoking, alcohol, excess weight, infections, varicocele and some medicines.

Pregnancy: still possible with most low counts, with treatment matched to the severity.

What does a low sperm count actually mean?

Your semen carries sperm, and the number of sperm in it is one important measure of fertility. The World Health Organization's 2021 guidelines set the lower normal limit at 16 million sperm per millilitre, with a total of about 39 million sperm in a full sample. When the concentration falls below this, doctors call it oligospermia, or simply a low sperm count. If no sperm are found at all, the term is azoospermia.

It helps to remember that a single number is never the whole story. Fertility depends on the count and on how well the sperm move, known as motility, their shape, known as morphology, and the health of the female partner too. A slightly low count with good movement is very different from a very low count with poor movement, which is why doctors read the full report rather than reacting to one figure.

What is considered a normal sperm count?

The WHO 2021 lower reference limits give a useful guide. The benchmarks are: a semen volume of 1.4 mL, a sperm concentration of 16 million per mL, a total sperm number of 39 million per ejaculate, total motility of 42 percent, progressive motility of 30 percent, normal morphology of 4 percent, and vitality of 54 percent. Being below one value does not automatically mean infertility. It simply flags an area to look at more closely, ideally with a doctor who reads the whole report together rather than one figure in isolation.

How is low sperm count classified by severity?

Grouping the count by severity helps decide treatment. Mild oligospermia, around 10 to 16 million per mL, often still allows natural conception. Moderate oligospermia, around 5 to 10 million per mL, may benefit from lifestyle changes or IUI. Severe oligospermia, under 5 million per mL, often calls for IVF with ICSI. Azoospermia means no sperm in the semen and needs specialist evaluation, although sperm can sometimes still be retrieved directly from the testicles.

What causes a low sperm count?

Sperm production is a sensitive process that takes around three months, so many things can lower the count. The causes generally fall into three groups: medical, lifestyle and environmental, and temporary.

Medical causes include a varicocele, an enlargement of the veins in the scrotum and the most common reversible cause. Others are hormonal imbalances, infections of the reproductive tract, undescended testicles, previous mumps, certain genetic conditions, diabetes, and blockages that stop sperm from reaching the semen. Some medicines, including certain steroids, chemotherapy and a few blood pressure drugs, can also reduce production.

Lifestyle and environmental causes include smoking, heavy alcohol, recreational drugs, being significantly overweight, chronic stress and lack of sleep. Heat is a quiet culprit too: frequent hot baths, laptops resting on the lap, tight underwear and long hours of sitting can warm the testicles enough to affect production. Exposure to pesticides, heavy metals and industrial chemicals plays a role for some men.

Because new sperm take about 70 to 90 days to mature, a fever, illness or stressful few months can show up as a low count and then recover on its own. This is exactly why doctors usually repeat the test before drawing any firm conclusions.

What are the symptoms of low sperm count?

For most men there are no symptoms at all, which is why a low count is so often discovered only when a couple has trouble conceiving. When signs do appear, they usually point to an underlying cause rather than the low count itself: swelling or a lump in the scrotum from a varicocele, reduced sex drive, difficulty with erections, low facial or body hair, or pain and swelling in the testicle area. Because the count itself is silent, testing is the only reliable way to know.

How is low sperm count diagnosed?

Diagnosis starts with a semen analysis. You provide a sample after 2 to 5 days without ejaculation, and a laboratory measures the count, motility, morphology, volume and more. Because results vary naturally from sample to sample, an abnormal report is almost always repeated after a few weeks to confirm it.

If the count is confirmed low, the doctor may add a hormone blood test for testosterone, FSH and LH, a scrotal ultrasound to look for a varicocele, and, in severe cases, genetic testing. A physical examination and a careful history of illnesses, medicines and lifestyle complete the picture. Testing both partners together saves time, which is why checking both partners early matters so much.

How is low sperm count treated?

The right treatment depends on the cause and the severity, and often a combination works best.

For mild and moderate cases, lifestyle changes are genuinely powerful. Stopping smoking, cutting alcohol, reaching a healthy weight, eating a diet rich in antioxidants from fruits, vegetables and nuts, exercising moderately, sleeping well and keeping the testicles cool can all lift the count over a few months.

When a specific cause is found, treating it can restore fertility: antibiotics for infections, hormone therapy for imbalances, and a minor surgery to repair a varicocele. When medicines and surgery are not enough, or the count is very low, assisted reproduction is the next step.

With moderate counts, IUI, which places washed and concentrated sperm directly into the uterus, can improve the odds. With severe counts, IVF with ICSI, where a single healthy sperm is injected directly into an egg, is highly effective and needs only a tiny number of sperm.

Can you get pregnant with a low sperm count?

Yes, and this is the most important message. A low count lowers the monthly chance of conception, but it rarely makes pregnancy impossible. Many couples conceive naturally with mild oligospermia, especially when the female partner is fertile and the timing is good. Even with very low counts, modern treatments like ICSI need only a handful of healthy sperm to create an embryo.

What matters is not panicking over one number. With the right diagnosis, a few months of healthy changes and the appropriate level of help, the great majority of couples affected by low sperm count go on to have a baby. If you are feeling unsure, gentle counselling can make the path forward much clearer.

Frequently asked questions about low sperm count

Is low sperm count permanent?

Often it is not. Many causes such as heat, smoking, alcohol, weight, infections and varicocele are reversible. Because sperm take about three months to mature, improvements usually appear two to three months after changes begin. Only some genetic or structural causes are permanent, and even then sperm can often be retrieved for IVF.

How can I increase my sperm count naturally?

Stop smoking, limit alcohol, reach a healthy weight, eat antioxidant rich foods, exercise moderately, sleep well, manage stress, and keep the testicles cool by avoiding tight underwear and laptop heat. These steps can meaningfully raise the count over two to three months, though severe cases may still need medical treatment.

How long does it take to improve sperm count?

Because a full cycle of sperm production lasts roughly 70 to 90 days, most lifestyle or medical changes need at least two to three months to show in a semen analysis. Doctors usually retest after about three months to measure real progress rather than day to day variation.

Does low sperm count affect the baby's health?

For most men, a low count does not affect the health of a baby once conception happens. In a small number of cases, very severe counts can be linked to genetic factors, which is why genetic testing is sometimes advised before IVF with ICSI. Your specialist will guide you if testing is needed.

Can stress cause low sperm count?

Yes, ongoing stress can lower the hormones that drive sperm production and reduce quality. It is usually one factor among several rather than the only cause. Managing stress through sleep, support and counselling can help, alongside other lifestyle changes. Emotional well-being and fertility are closely linked.

What sperm count is needed to conceive naturally?

There is no single magic number, but chances are generally better above 15 million per mL with good motility. Couples conceive at lower counts too, especially when the female partner is fertile. If natural conception has not happened after several months, a semen analysis and a doctor's review are the sensible next step.

Key takeaways

Low sperm count means under 16 million sperm per mL (WHO 2021). It is common and usually not the end of the road.

A semen analysis, repeated to confirm, is the first and most important test.

Many causes such as heat, smoking, alcohol, weight, infections and varicocele are reversible.

Treatment ranges from lifestyle changes and surgery to IUI and IVF with ICSI, matched to the severity.

Pregnancy is possible with most low counts, and ICSI needs only a few healthy sperm.

Test both partners early and seek counselling. It saves months of uncertainty.

Related reading

Semen Analysis Test, What It Checks, Normal Values and How to Read Your Report: https://parivarsaathi.com/blog/semen-analysis-test-what-it-checks-normal-values-and-how-to-read-your-report

Male Fertility: When Should Men Get Tested?: https://parivarsaathi.com/blog/male-fertility-when-should-men-get-tested

Men's Role in Fertility: Why OPD Checks Matter for Both Partners: https://parivarsaathi.com/blog/mens-role-in-fertility-why-opd-checks-matter-for-both-partners

How Lifestyle Choices Affect Fertility in Men and Women: https://parivarsaathi.com/blog/how-lifestyle-choices-affect-fertility-in-men-and-women

Can Stress Affect Fertility? Understanding the Connection Between Emotional Well-Being and Reproductive Health: https://parivarsaathi.com/blog/can-stress-affect-fertility-understanding-the-connection-between-emotional-well-being-and-reproductive-health

When Should You Consider IVF?: https://parivarsaathi.com/blog/when-should-you-consider-ivf

IVF India, Complete Guide for Process, Cost and Success Rates: https://parivarsaathi.com/blog/ivf-india-complete-guide-for-process-cost-and-success-rates

Medical references

World Health Organization, WHO Laboratory Manual for the Examination and Processing of Human Semen, 6th edition (2021). NICE, Fertility problems: assessment and treatment (CG156). ASRM, Diagnostic Evaluation of the Infertile Male. Mayo Clinic, Low sperm count, Symptoms and causes.

Written by: Parivar Saathi Editorial Team. Editorial review by Dr. Deeksha Goswami, Senior Fertility Counsellor. Published 20 June 2026. This article is for general information and education only and is not a substitute for professional medical advice, diagnosis or treatment. Always consult a qualified doctor or fertility specialist about your individual situation.