Teratospermia (also known as “teratozoospermia”) is a condition characterized by abnormal sperm morphology — meaning that many of a person’s sperm are the incorrect size, shape, or structure. Abnormalities could include a defect in the head, midpiece, or tail of the sperm. Teratospermia may have an adverse effect on fertilization, and can be related to genetic traits, chronic diseases, alcohol and drug use, and obesity.

What is teratozoospermia?

Teratozoospermia (also known as “teratospermia”) is a fertility condition defined by abnormal sperm morphology (shape and structure). Patients diagnosed with this condition experience an increase in abnormally shaped sperm in their semen. According to the World Health Organization (WHO), normal sperm morphology ranges between 4% and 14% of a male’s sperm count.

Teratozoospermia is typically characterized by a defect on the head, midpiece, or tail of the sperm. Those with this condition are less likely to conceive, although it’s not impossible — studies show that about ⅓ of people with zero morphology can still conceive naturally. Teratozoospermia can be diagnosed with a semen analysis (SA).

Teratozoospermia in male fertility

Patients with teratozoospermia can experience lower fertility because abnormally shaped sperm cells are less likely to fertilize the egg.

Normal sperm typically have an oval shaped head and a distinct cap covering the sperm head. Furthermore, sperm should have a straight neck and one tail. Lastly, there should be no drops of fluid in the head. With teratozoospermia, however, at least one of these conditions is not met. 

Nevertheless, patients with this condition may still be able to conceive naturally as long as other sperm factors are normal, including sperm motility and sperm count. Couples can also turn to assisted reproductive technology (ART) procedures to achieve pregnancy. 

Causes of teratozoospermia

Teratozoospermia can be caused by a number of factors, including lifestyle choices, genetic disorders, and chronic diseases and infections. Unhealthy lifestyle choices such as excessive smoking, drinking, and an unbalanced diet may all contribute to this condition. In addition, testicular trauma can also cause teratozoospermia. Lastly, it is important to note that as patients age, their ability to produce quality sperm diminishes. 

Back to Glossary