Teratozoospermia: Definition, Causes, and Effective Treatments


Teratozoospermia, also known as teratospermia, is a condition characterised by abnormal sperm morphology. We spoke to Dr John Peay about how it affects male conception and treatment options to improve fertility.

What is Teratozoospermia?

This means that a significant number of a person’s sperm are the wrong size, shape or structure. Abnormalities can include defects in the head, middle piece or tail of the sperm.


What does teratozoospermia involve?

Defined by abnormal sperm shape and structure, teratozoospermia is a fertility condition where there is an increase of atypically shaped sperm in the semen.

According to the World Health Organisation (WHO), normal sperm morphology varies between 4% and 14% of a man’s total sperm count.

Generally, this condition is characterised by defects in the head, midpiece or tail of the sperm. Although it reduces the likelihood of conception, it does not make conception completely impossible; studies indicate that about a third of people with zero morphology can still conceive naturally.

How is it diagnosed?

Teratozoospermia is diagnosed by means of a seminogram (semen analysis).

Embryologists specialised in andrology perform a seminal lavage to evaluate the percentage of healthy spermatozoa and thus suggest the most suitable reproductive technique for patients.

sperm selection

Teratozoospermia and Male Fertility

Patients with teratozoospermia may experience a decrease in fertility, as abnormally shaped sperm are less likely to fertilise the egg.

A healthy sperm generally has an oval head, should have a straight neck and a tail. In addition, there should be no fluid droplets in the head. In teratozoospermia, however, at least one of these characteristics is not met.

Can pregnancy be achieved with teratozoospermia?

In consultation, we see that patients with this condition can still achieve conception naturally if other sperm factors are normal, including sperm motility and sperm count.

Techniques and treatments to achieve pregnancy with the help of Assisted Reproduction

According to Dr. Peay, in cases of teratozoospermia, where the sperm morphology is abnormal, several fertility techniques and treatments can be recommended:

  • Intracytoplasmic Sperm Injection (ICSI): this technique is a variant of In Vitro Fertilisation (IVF) and is commonly used in cases of teratozoospermia. It involves directly injecting a selected sperm into an egg. ICSI is useful because a normal-appearing sperm is selected for fertilisation, avoiding the limitations of abnormal morphology.
  • In Vitro Fertilisation (IVF): Although IVF itself does not solve the problem of sperm morphology, it can be combined with ICSI to increase the chances of success.
  • Advanced Sperm Selection: Techniques such as microfluidic sperm selection or sperm DNA fragmentation can help select sperm with better morphology and less DNA damage for use in IVF or ICSI.
  • Preimplantation genetic diagnosis (PGD): In cases of severe teratozoospermia, PGD may be recommended to screen embryos for genetic abnormalities prior to implantation.

Each case of teratozoospermia is unique, and the most appropriate treatment plan will depend on several factors, including the severity of the condition and the overall health of the couple. Therefore, a detailed evaluation by a fertility specialist is important to determine the best treatment strategy.

Causes of Teratozoospermia

Teratozoospermia is associated with genetic factors, chronic diseases, alcohol and drug use, and obesity.

These can be summarised as follows:

  1. Genetic factors: chromosomal or genetic abnormalities can cause defects in sperm morphology. This may include abnormalities in the sex chromosomes (e.g. Klinefelter’s syndrome) or specific genetic mutations that affect sperm production.
  2. Testicular injury: Injury to the testicles due to trauma, infection (epididymitis or STIs), previous surgery, radiotherapy or chemotherapy may affect sperm production and result in abnormal sperm forms.
  3. Exposure to toxins: Exposure to environmental toxins such as industrial chemicals, heavy metals, pesticides, and cigarette smoking can affect sperm production and quality.
  4. Hormonal factors: Hormonal imbalances, such as abnormal levels of testosterone or other reproductive hormones.
  5. Excessive heat: Excessive heat in the testicles, whether due to tight clothing, frequent hot baths, or prolonged use of computers on the lap, can negatively affect sperm production and morphology.
  6. Lifestyle and nutritional factors: Factors such as obesity, a diet deficient in essential nutrients, excessive alcohol consumption, chronic stress and smoking may contribute to theratozoospermia.

19 Feb: How men’s age affects men’s fertility: care and advice

We speak to Dr. Peay about age and men’s fertility: how does age affect reproductive ability regarding men?

07 Feb: How to select the best sperm in a fertility treatment

We talk to Dr. Alvaro Martinez about the importance of selecting the best sperm and the techniques he uses to make it possible.

24 Nov: Fertile Chip: Optimizing Success in Assisted Reproduction Treatments

FertileChip, an innovative device that facilitates the sperm selection with enhanced mobility and reduced DNA fragmentation.

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