Asthenozoospermia: Causes, Testing, and Fertility

A semen sample may contain sperm that:

• do not move;
• move slowly;
• move in circles;
• move without progressing forward;
• have weak or irregular tail movement.

Reduced motility may make it harder for sperm to travel through the cervix, uterus, and fallopian tube to reach an egg.

• astheno-, meaning weak;
• zoo-, referring to living cells or spermatozoa;
• -spermia, referring to sperm in semen.

It is generally uncountable:

• He was diagnosed with asthenozoospermia.
• Asthenozoospermia may reduce the chance of natural conception.
• The semen analysis showed reduced progressive motility.

The adjective is asthenozoospermic:

• an asthenozoospermic sample;
• asthenozoospermic findings.

Common expressions include:

• reduced progressive motility;
• low total motility;
• poor sperm movement;
• isolated asthenozoospermia;
• severe motility impairment;
• repeat semen analysis.

Progressive Motility

Progressively motile sperm move forward in a straight or broadly forward direction.

This type of movement is important because sperm must travel through the reproductive tract to reach an egg.

Non-Progressive Motility

Non-progressively motile sperm move but do not travel forward effectively.

They may:

• move in small circles;
• vibrate in place;
• move only slightly;
• follow an irregular path without meaningful progression.

Immotile Sperm

Immotile sperm do not move.

An immotile sperm may be alive but unable to move, or it may be nonliving. Additional laboratory testing may sometimes distinguish between these possibilities.

A fresh semen sample is examined under a microscope, and the laboratory estimates:

• total motility;
• progressive motility;
• non-progressive motility;
• proportion of immotile sperm.

Results may be affected by:

• collection method;
• time between collection and testing;
• sample temperature;
• incomplete collection;
• recent fever or illness;
• laboratory technique;
• natural variation between samples.

For this reason, one abnormal test may need to be repeated.

• varicocele;
• genital or reproductive-tract infection;
• inflammation;
• oxidative stress;
• testicular injury;
• hormonal conditions;
• genetic differences;
• structural sperm-tail abnormalities;
• prolonged heat exposure;
• smoking;
• heavy alcohol use;
• recreational drugs;
• some medications;
• chemotherapy or radiation;
• increasing age.

In many cases, no single cause is identified.

It may affect testicular temperature, blood flow, and oxidative balance. These changes may reduce sperm:

• concentration;
• motility;
• morphology;
• DNA quality.

Not every varicocele causes fertility problems, and treatment is not necessary in every case.

A clinician may consider symptoms, testicular examination, semen results, fertility history, and reproductive goals before recommending treatment.

Possible associated symptoms include:

• genital or pelvic pain;
• painful urination;
• painful ejaculation;
• swelling;
• unusual discharge;
• fever.

Some infections produce no obvious symptoms.

Antibiotics are helpful only when a bacterial infection is identified or strongly suspected. They do not treat every case of low sperm motility.

Repeated or prolonged heat exposure may affect semen quality. Possible sources include:

• frequent hot tubs or saunas;
• occupational heat;
• prolonged fever;
• certain working environments;
• repeated pressure and heat from long-distance cycling.

Environmental toxins, pesticides, solvents, and heavy metals may also influence sperm health in some situations.

Reducing an exposure may help, but improvement is not guaranteed.

• smoking;
• frequent heavy alcohol use;
• anabolic steroid use;
• some recreational drugs;
• inadequate sleep;
• obesity;
• poor metabolic health;
• nutritional deficiency;
• untreated chronic illness.

Lifestyle changes may support overall reproductive health, but they do not cure every cause of asthenozoospermia.

Commercial supplements should not replace medical evaluation, especially because evidence for many fertility products is limited.

This finding requires careful confirmation because immotile sperm may be:

• alive but unable to move;
• structurally unable to move;
• damaged during collection or transport;
• nonliving.

A laboratory may perform a sperm-vitality test to determine how many immotile sperm are alive.

Severe or complete motility loss may sometimes be linked to genetic or structural abnormalities of the sperm tail.

• repeat semen analysis;
• medical and fertility history;
• physical examination;
• medication and substance review;
• recent illness or fever history;
• hormone testing;
• assessment for varicocele;
• infection testing when appropriate;
• genetic testing in selected severe cases;
• sperm-vitality testing.

Because semen results naturally vary, diagnosis should not rely on one sample alone unless the finding is very clear and clinically urgent.

Reduced progressive motility may lower the likelihood of fertilization, particularly when it occurs together with:

• low sperm concentration;
• abnormal morphology;
• low semen volume;
• reproductive-tract obstruction;
• fertility factors affecting the other partner.

However, natural pregnancy may still occur when enough moving sperm are present.

Motility alone cannot predict pregnancy with certainty.

Possible approaches include:

• treating infection when present;
• reviewing medications;
• managing a clinically significant varicocele;
• stopping smoking;
• reducing harmful substance use;
• avoiding excessive heat;
• improving sleep and metabolic health;
• treating hormone disorders;
• repeating semen analysis;
• using assisted reproduction when needed.

There is no single medication that restores motility in every case.

Because sperm development takes several weeks, any improvement may take months to appear in a new semen analysis.

Intrauterine Insemination

During intrauterine insemination, a prepared sample containing the most motile sperm is placed inside the uterus near ovulation.

Its usefulness depends heavily on the total number of moving sperm after preparation.

In Vitro Fertilization

During in vitro fertilization, sperm and eggs are placed together in a laboratory.

Reduced motility may make natural laboratory fertilization less likely when few sperm can reach or penetrate an egg.

Intracytoplasmic Sperm Injection

During intracytoplasmic sperm injection, one sperm is injected directly into an egg.

ICSI may be considered when motility is severely reduced, previous fertilization has failed, or few usable sperm are available.

ICSI bypasses the need for the sperm to travel to and enter the egg independently, but it does not guarantee embryo development or pregnancy.

Related terms include:

• oligozoospermia: low sperm concentration;
• teratozoospermia: abnormal sperm shape;
• azoospermia: no sperm detected in semen;
• necrospermia: unusually high proportion of nonliving sperm.

When low count, poor movement, and abnormal shape occur together, the combined finding may have a greater effect on fertility than one abnormality alone.

• anxiety;
• shame;
• concerns about masculinity;
• fear of infertility;
• relationship tension;
• pressure during timed intercourse.

Asthenozoospermia is a laboratory and reproductive-health finding. It does not measure sexual ability, erection quality, ejaculation, attraction, masculinity, or personal worth.

Fertility evaluation should consider all relevant partners without blame.

It always causes infertility.
No. Natural pregnancy may still occur.

Poor sperm movement causes erectile dysfunction.
No. Sperm motility and erection are different functions.

One semen analysis gives a final answer.
No. Results can vary, and repeat testing may be necessary.

Every immotile sperm is dead.
No. Some sperm may be alive but unable to move.

ICSI is required in every case.
No. Treatment depends on severity and the complete fertility assessment.

1. Asthenozoospermia means that sperm movement is lower than expected.
2. His semen analysis showed reduced progressive motility.
3. Can someone with asthenozoospermia conceive naturally?
4. The clinician repeated the test after a recent fever.
5. A varicocele may contribute to poor sperm movement.
6. Sperm-vitality testing can examine whether immotile sperm are alive.
7. ICSI may be considered when motility is severely reduced.
8. Understanding asthenozoospermia helps readers distinguish sperm movement from count, shape, erection, and masculinity.

It usually does not affect sexual desire, erection, orgasm, ejaculation, attraction, or enjoyment of sexual activity. A person may have typical sexual function while having reduced sperm motility.

Understanding asthenozoospermia helps people discuss fertility without shame and prevents one semen-analysis result from being treated as a complete judgment about reproductive ability or personal worth.