Sperm DNA Fragmentation

Sperm DNA fragmentation refers to damage in the genetic material (DNA) of the spermand can be factor in male infertility. Here we’ll explore what it is, how it’s measured and how it can be treated. 

What is sperm DNA fragmentation?

Sperm DNA fragmentation is when the DNA within the head of the sperm is fragmented or damaged. The damage can occur during sperm maturation or from external factors like oxidative stress (a condition caused by low levels of antioxidants)1. Sperm DNA damage is not known to have an impact on the fertilisation of eggs, however high levels of sperm DNA fragmentation may negatively affect embryo development, implantation and pregnancy2. High levels of this are prevalent in men with low quality semen but they may also be present in otherwise normal semen samples.

What are the causes of sperm DNA fragmentation?

Sperm DNA fragmentation is caused by damage through oxidative stress. This in turn can be caused by inflammation or infections in the male genitals3 (like sexually transmitted diseases), varicoceles (enlarged blood vessels in the testicle), environmental and lifestyle factors, smoking and recreational drug use4

How do you test for sperm DNA fragmentation?

Testing for this involves a non-invasive procedure performed as an additional diagnostic tool and is not included in the standard semen analysis. There are no risks to the test as it uses a small sample of sperm that would not be used for treatment1. Several different methods are available for assessing sperm DNA fragmentation and the results should be discussed with your clinician in order to understand if they are within normal range. 

When might the test be offered?

Testing may be offered in cases of unexplained infertility or recurrent miscarriages. It may also be offered following a fertility treatment if there has been poor fertilisation, poor embryo development or after multiple cycles of IVF if you have not fallen pregnant. 

How can sperm DNA fragmentation be treated?

Changes to lifestyle is one of the most fundamental and simple ways to improve sperm quality and DNA damage. Men with low semen quality and high DNA fragmentation are recommended to quit smoking, reduce alcohol consumption, exercise and manage their weight4. If an infection is present it should be treated with a course of antibiotics3 and if varicoceles are the cause then these can be surgically repaired3. A common treatment that may be offered is an antioxidant therapy as oxidative stress may be caused by low levels of antioxidants, however currently there is little evidence to support that oral antioxidants can repair DNA damage or increase chances of having a baby5

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