Asthenospermia, more precisely asthenozoospermia, means sperm motility is below the expected reference range. WHO 2021 reports lower reference values of about 42% total motility and 30% progressive motility. The term does not tell you why motility is low or whether pregnancy is impossible. Sample handling, fever, abstinence duration, varicocele, inflammation, oxidative stress and primary sperm disorders can all affect movement.

This page focuses on the semen-report term asthenospermia. For a broader discussion of causes, treatment choices and practical ways motility is interpreted with count and morphology, see ‘Low Sperm Motility: Causes and Treatment.’

What is Asthenospermia?

Asthenozoospermia is a descriptive semen term for reduced sperm movement. The report may separate progressive sperm, non-progressive sperm and immotile sperm. In severe cases, vitality testing is important because a live sperm that does not move is different from a dead sperm.

How to understand the report

Common reasons

• Recent fever.
• Delayed semen processing or temperature exposure.
• Long abstinence in some men.
• Varicocele.
• Smoking/oxidative stress and poor metabolic health.
• Inflammation or infection in selected men.
• Rare flagellar or genetic disorders when motility is profoundly reduced.

What tests may be needed

Review collection and laboratory timing first. Persistent severe motility reduction may need vitality testing, examination and targeted infertility evaluation. Advanced genetic evaluation is not routine for mild isolated motility reduction but may be relevant in rare complete or near-complete motility disorders.

Treatment and fertility options

Treat correctable causes and optimise the couple’s fertility strategy. If motility remains very low, IUI may be less useful when the post-wash motile sperm count is poor, while IVF/ICSI can bypass much of the movement requirement. The exact route should be chosen with the reproductive team.

When asthenospermia needs more than a repeat report

• Progressive motility is extremely low or the same abnormality persists after a well-collected repeat sample.
• Most or all sperm are immotile, because vitality testing is needed to distinguish live immotile sperm from necrozoospermia.
• The result remains poor even when sample transport time and temperature were appropriate and there was no recent high fever.
• Motility loss occurs with low count, poor morphology, a clinical varicocele or signs of broader testicular dysfunction.
• The couple is planning IUI or IVF/ICSI, where the absolute number of usable motile sperm and previous fertilisation history affect the next step.

When should sperm motility be rechecked?

Motility is influenced by biological variation as well as collection, transport time and temperature. If the first result is abnormal but the situation is otherwise stable, the WHO 2025 infertility guideline suggests repeating the semen analysis after a minimum of about 11 weeks. Near-zero motility or an all-immotile sample deserves earlier specialist review and vitality testing rather than simply waiting for another report.

When almost all sperm are immotile

If a report shows extremely poor movement, the next question is whether the sperm are alive. Vitality testing can identify live but immotile sperm and distinguish that situation from necrozoospermia, where a high proportion of sperm are dead. This distinction matters for diagnosis and for assisted-reproduction laboratories trying to select viable sperm.

Severe asthenozoospermia can occasionally reflect a primary sperm-tail or ciliary disorder, but far more common explanations include biological variation, sample-handling problems, recent fever and broader testicular dysfunction. A repeat high-quality semen analysis is therefore important before a rare diagnosis is assumed.

Assisted reproduction can sometimes overcome severe motility problems, especially with ICSI, but that does not make the male evaluation unnecessary. Very poor motility may still reveal a treatable cause, a sample-quality issue or a rare sperm-function disorder that affects counselling and laboratory planning.

If motility remains very low despite good sample handling, the urologist also looks at the total number of progressively motile sperm available. This practical number often matters more for natural conception or IUI planning than the motility percentage viewed in isolation.

What to bring for consultation

Bring these if available:

• Semen reports showing progressive and total motility, plus vitality if nearly all sperm were immotile.
• Abstinence duration and sample-transport/processing details for the abnormal test.
• Dates of recent fever or illness, and any symptoms of genital or urinary infection.
• Scrotal Doppler, hormone reports and current medicines including testosterone or anabolic steroids.
• Previous fertility-treatment results and the partner’s fertility evaluation if available.

FAQs

Related reading

• Low Sperm Motility: Causes and Treatment
• Semen Analysis Report Explained
• Oligoasthenoteratospermia Explained
• Varicocele and Male Infertility
• Fever and Sperm Count: When to Repeat Test
• Urologist in Latur

References

• World Health Organization. WHO laboratory manual for the examination and processing of human semen, 6th ed https://www.who.int/publications/i/item/9789240030787
• World Health Organization. Guideline for the prevention, diagnosis and treatment of infertility. 2025 https://www.who.int/publications/i/item/9789240115774
• European Association of Urology. EAU Guidelines on Sexual and Reproductive Health: Male Infertility. 2026 https://uroweb.org/guidelines/sexual-and-reproductive-health/chapter/male-infertility
• American Urological Association/American Society for Reproductive Medicine. Diagnosis and Treatment of Infertility in Men: AUA/ASRM Guideline (2020; Amended 2024) https://www.auanet.org/documents/Guidelines/PDF/2024%20Guidelines/Male%20Infertility%20Unabridged%20Final.pdf