Teratozoospermia: Causes, Diagnosis, and Fertility

A sperm cell normally has:

• a smooth oval head;
• a well-formed midpiece;
• a long, uncoiled tail.

Atypical sperm may have a head that is too large, too small, irregular, double, or misshapen. The midpiece may be thick or bent, and the tail may be short, coiled, doubled, or absent.

Some abnormal sperm are found in almost every semen sample. The diagnosis depends on the proportion of sperm considered normally shaped under laboratory criteria.

• terato-, meaning malformed or abnormally developed;
• zoo-, referring to living cells or spermatozoa;
• -spermia, referring to sperm in semen.

It is generally uncountable:

• He was diagnosed with teratozoospermia.
• Teratozoospermia may affect fertility.
• The laboratory reported reduced normal sperm morphology.

The adjective is teratozoospermic:

• a teratozoospermic semen sample;
• teratozoospermic findings.

Common expressions include:

• isolated teratozoospermia;
• severe teratozoospermia;
• abnormal sperm morphology;
• reduced normal forms;
• morphology assessment;
• semen-analysis result.

Head

The head contains genetic material and a cap-like structure called the acrosome, which contains enzymes involved in fertilization.

Possible head abnormalities include:

• unusually large or small size;
• irregular shape;
• double heads;
• tapered heads;
• abnormal acrosomes;
• vacuoles or internal irregularities.

Midpiece

The midpiece contains structures that help provide energy for movement.

Possible abnormalities include:

• thickening;
• bending;
• asymmetrical attachment;
• excess residual cytoplasm.

Tail

The tail propels the sperm forward.

Possible abnormalities include:

• short tails;
• coiled tails;
• multiple tails;
• sharply bent tails;
• absent tails.

A single sperm may have abnormalities in more than one area.

A laboratory professional prepares and stains a semen sample, then examines sperm under a microscope. The sperm are compared with established shape criteria.

The report may provide the percentage of sperm considered normally formed.

Morphology assessment is partly subjective and may vary because of:

• laboratory technique;
• staining method;
• examiner experience;
• classification criteria;
• natural variation between samples.

For this reason, one abnormal result is often interpreted cautiously and may be repeated.

Under these standards, only sperm meeting narrow measurements for the head, midpiece, and tail are counted as normal. This can produce a low percentage of normal forms even when many sperm remain capable of movement.

A low morphology percentage should therefore not be interpreted by itself as proof of infertility.

The result is more useful when considered with sperm concentration, total count, motility, medical history, and the couple’s reproductive circumstances.

Its effect on natural fertility may vary.

Some people with isolated teratozoospermia achieve pregnancy without treatment. Others may experience difficulty, especially when additional fertility factors are present.

The diagnosis should therefore be understood as one laboratory finding rather than a complete explanation of reproductive ability.

• genetic factors;
• varicocele;
• testicular heat exposure;
• smoking;
• heavy alcohol use;
• recreational drugs;
• certain medications;
• environmental toxins;
• fever or recent illness;
• oxidative stress;
• testicular injury;
• hormonal disorders;
• infection or inflammation;
• cancer treatment;
• increasing age.

In many cases, no single cause is identified.

Because sperm development takes several weeks, illness or exposure may affect semen results for months afterward.

It may alter testicular temperature, blood flow, or oxidative balance and may be associated with changes in:

• sperm count;
• movement;
• morphology;
• DNA integrity.

Not every varicocele causes infertility, and not every person with teratozoospermia has a varicocele.

Clinical examination and, in selected cases, imaging may be used to assess it.

• smoking;
• frequent heavy alcohol use;
• anabolic steroids;
• some recreational drugs;
• repeated high heat exposure;
• poor sleep;
• obesity;
• untreated illness;
• occupational toxin exposure.

Improving health habits may support semen quality, but lifestyle change does not guarantee that morphology will become normal.

Commercial supplements marketed for sperm shape often have limited or inconsistent evidence.

A clinician may also review:

• fertility history;
• previous pregnancies;
• medical and surgical history;
• medication and substance use;
• occupational exposures;
• recent fever or illness;
• testicular examination;
• hormone testing;
• genetic testing in selected cases;
• ultrasound when structural problems are suspected.

Because semen values naturally fluctuate, repeat testing may be recommended after an appropriate interval.

• moving efficiently;
• reaching the egg;
• attaching to the egg;
• undergoing the acrosome reaction;
• penetrating the egg’s outer layers;
• completing fertilization.

However, semen contains many sperm, and only one is needed to fertilize an egg.

A low percentage of normal forms does not mean that every sperm is abnormal or incapable of fertilization.

• sperm count is adequate;
• motility is good;
• ovulation occurs regularly;
• fallopian tubes are open;
• intercourse is appropriately timed;
• no major additional fertility factor is present.

The chance of pregnancy cannot be estimated accurately from morphology alone.

A fertility assessment should consider both partners rather than focusing only on one semen result.

Management may include:

• stopping smoking;
• reducing harmful substance use;
• treating infection when present;
• managing a varicocele in selected cases;
• reviewing medications;
• reducing excessive heat exposure;
• improving general metabolic health;
• repeating semen analysis;
• fertility treatment when needed.

Treatment should address an identifiable cause rather than assuming that every low morphology result requires intervention.

Intrauterine Insemination

During intrauterine insemination, prepared sperm are placed inside the uterus near the time of ovulation.

Its usefulness depends on the total number of moving sperm and other fertility factors, not morphology alone.

In Vitro Fertilization

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

Fertilization may still be reduced when sperm morphology is severely abnormal, especially if other sperm problems are present.

Intracytoplasmic Sperm Injection

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

ICSI may be considered in severe male-factor infertility, previous fertilization failure, or selected cases with major morphology abnormalities.

ICSI bypasses several natural fertilization steps, but it does not guarantee embryo development or pregnancy.

Other terms include:

• oligozoospermia: low sperm concentration;
• asthenozoospermia: reduced sperm movement;
• azoospermia: no sperm detected in semen;
• necrospermia: unusually high proportion of nonliving sperm.

A person may have one abnormality alone or several together.

When low count, poor motility, and abnormal morphology occur together, the combined condition may have a greater effect on fertility.

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

Teratozoospermia is a medical finding, not a measure of masculinity, sexual ability, attraction, or personal worth.

Open communication and balanced fertility counseling may reduce blame and help both partners understand available options.

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

Abnormal shape means abnormal sexual performance.
No. Sperm morphology is unrelated to erection, desire, ejaculation, or sexual technique.

One semen analysis provides a final diagnosis.
No. Semen results can vary, and repeat testing may be needed.

Low morphology proves that a future child will have abnormalities.
No. Morphology mainly describes sperm shape under a microscope and does not directly predict a child’s health.

ICSI is always required.
No. Treatment depends on the full fertility evaluation.

1. Teratozoospermia means that a low proportion of sperm have typical morphology.
2. His semen analysis showed normal concentration but abnormal sperm shape.
3. Can someone with teratozoospermia conceive naturally?
4. The laboratory examined sperm heads, midpieces, and tails.
5. One abnormal morphology result may need confirmation with repeat testing.
6. A varicocele may be associated with reduced semen quality.
7. ICSI may be considered when severe male-factor infertility is present.
8. Understanding teratozoospermia helps readers distinguish sperm shape from count, movement, sexual performance, and masculinity.

It does not usually affect sexual desire, erection, orgasm, ejaculation, attraction, or the ability to enjoy sexual activity. A person may have typical sexual function while having abnormal sperm morphology.

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