Sperm DNA Fragmentation

Sperm DNA Fragmentation

The integrity of DNA in the sperm is important for successful fertilization and embryo development. Sperm DNA fragmentation is a term used to imply abnormal DNA within the sperm, which in turn might lead to male subfertility, IVF failure, and miscarriage. A standard semen analysis done for sperm concentration, motility analysis, and morphology evaluation cannot evaluate the sperm at the molecular level and as a result, doesn’t help the detection of DNA fragmentation.

Studies indicate that:

• High sperm DNA fragmentation alters blastocyst development
• Higher the DNA fragmentation levels, greater the chances of failed assisted conception treatment and miscarriage
• Sperm DNA fragmentation is greater in subfertile men with abnormal sperm parameters
• Men with normal sperm parameters are also found to have elevated sperm DNA fragmentation

Benefits of the sperm DNA fragmentation test

• Provides a consistent evaluation of sperm DNA integrity that may help to identify men who are at risk of subfertility
• Provides information that helps in the clinical diagnosis, management, and treatment of male fertility
• Provides prognostic value in evaluating the outcome of supported conception treatment
• Elevated rates of sperm DNA fragmentation and pregnancy potential
• Normal, healthy pregnancies happen in couples where the male partner has a high ratio of sperm with fragmented DNA, although the chances are substantially reduced, as the ratio of sperm bearing low levels of DNA fragmentation is much lower
• Embryos developed from sperm with highly fragmented DNA have a poor diagnosis
• DNA fragmentation could end in the commencement of apoptosis (natural cellular death) and mutations resulting in blastocyst arrest, miscarriage and abnormalities in the offspring
• Sperms with high DNA fragmentation fertilizing younger oocytes than older oocytes carry a better prognosis of a successful pregnancy, as they are much more effective at DNA repair of defective sperm

Causes of Sperm DNA Fragmentation

In men, the major influencing factor for sperm DNA fragmentation is oxidative stress, which can be linked with one or more of the following:

• Infection
• Pyrexia
• Elevated testicular temperature
• Recreational drugs
• Smoking
• Alcohol
• Stress
• Diet
• Environmental and occupational pollutants
• Advanced chronological age
• Varicocele

Indications for men who may benefit from the Sperm DNA Fragmentation test

• Unexplained infertility
• Stunted embryo development
• Mediocre blastocyst development
• Multiple failed IVF/ICSI treatments
• Recurring miscarriage
• Advanced chronological age
• Varicocele
• Poor semen Quality
• Exposure to harmful substances

Treatment of high sperm DNA fragmentation

It depends largely on the cause. If the damage is caused due to free radicals, a change in lifestyle and diet devised to protect against oxidative stress might help decrease the levels of DNA fragmentation. Other treatment options include:

• Antibiotics in the co-existence of an infection
• Lifestyle changes – drugs, smoking and work
• Diet – fresh foods, especially those containing antioxidants and vitamin C & E
• Varicocele surgery
• Testicular aspiration of sperm (DNA damage occurs at the post-testicular level; hence testicular sperm might have a healthier DNA integrity than ejaculated sperm)

Initiatives to decrease the levels of fragmentation can be evaluated by undertaking a second test three months later.

What is the Sperm Comet test?

It is a second-gen sperm DNA test. It identifies the sperm with DNA damage and tells how much DNA damage each sperm have. A Sperm Comet test result of 45% implies that there is an average of 45% DNA damage in each sperm that was evaluated. Sperm are stained with a fluorescent probe that interacts with the DNA molecule. The fluorescence indicator changes when the DNA is fragmented, and this is observed using a flow cytometer.