Your Test Results Explained

Your test results provide important information about your reproductive health which can help you make informed decisions about lifestyle changes or treatments to improve your fertility.

Your test results provide important information about your reproductive health. Male fertility problems can be caused by physical issues which reduce the likelihood of the sperm reaching and fertilising the egg, or poor sperm DNA quality which reduces the likelihood of a fertilised egg achieving a full-term pregnancy. Your test results will enable you to make smart lifestyle choices to improve your fertility and informed decisions about further investigation or treatment.

Your Test Results Explained

SpermComet® Test Results

SpermComet® measures the amount of sperm DNA fragmentation in your sample. Three different measures of DNA fragmentation are calculated and compared against an Examen reference range. The Examen reference range was developed by comparing a group of men who successfully fathered children in a year or less against a group of men having fertility treatment. The reference range cut-off represents the point that differentiates most clearly between the fertile and infertile men.

What do your test results mean?

Comet Plot

This is a graph of the percentage of sperm in your sample with different amounts of DNA fragmentation. The Comet Plot shows the extent of fragmentation throughout your sample. Your Comet plot is compared with a reference Comet Plot for a typical fertile man. Most of a fertile man’s sperm have low levels of DNA fragmentation. In contrast, an infertile man has fewer sperm with low fragmentation and more sperm with higher fragmentation (Figure 1).

Comet Score

This is the average amount of DNA fragmentation per sperm in your sample. It is a summary measure of the ‘typical’ amount of DNA fragmentation in your sample. A Comet Score of up to 26% is considered fertile (Table 1). If your Comet Score is borderline, a few percent above or below 26%, the Low and High DNA Damage results provide additional data to help confirm your diagnosis.

Results above the fertile range indicate an increased risk of male infertility, miscarriage and IVF failure. High DNA fragmentation is often associated with lifestyle factors including smoking, excessive alcohol intake, recreational drug use, anabolic steroid use or poor diet. It may also indicate a medical issue such as varicocele or infection.

Low DNA Damage (%)

This is the percentage of sperm in your sample with good quality DNA needed for a successful pregnancy. A Low DNA Damage result of 74% or more is considered fertile.

High DNA Damage (%)

This the percentage of sperm in your sample with badly fragmented DNA unlikely to lead to a successful pregnancy. A High DNA Damage result of 4% or less is considered fertile.

What now?

Consider your lifestyle

Sperm are sensitive and their quantity and DNA quality can be affected by a range of medical problems and lifestyle factors. The good news is that you make new batches of sperm every three months and by making simple lifestyle changes you can help improve the quantity and DNA quality of your sperm.

Smoking over 20 cigarettes a day reduces sperm count and motility. Tobacco contains over 4,000 ingredients and lots of them are toxic to sperm. Smoking also produces ‘free radicals’ that damage the sperm’s DNA. Smokers often have lower sperm counts and slower swimming sperm.

Drinking more than 2 pints of beer or 1 large glass of wine a day increases your risk of infertility. Alcohol reduces sperm count and motility. UK guidelines say that men trying for a baby should not drink more than 3-4 units of alcohol a week.

Recreational drugs. Cannabis changes the way sperm act making it harder for them to find the egg and fertilize it when they do. Regular cannabis use over a few years can permanently reduce a man’s ability to make sperm.

Diet.  Eating a healthy balanced diet is important for healthy sperm. Sperm need lots of different nutrients to function properly. Your diet should include:

  • Lots of fruit and steamed vegetables
  • Some starchy foods like bread, rice, potatoes and pasta
  • Some protein like meat, fish, eggs and beans
  • Some milk, yoghurt and cheese
  • Not too much fat, sugar or salt

Weight. Having a body mass index of over 25, may affect the quantity and DNA quality of your sperm.

Stress can limit sperm production and impact DNA quality by producing free radicals. Taking some of the stress out of your life can go a long way to improving your fertility.

Heat. Sperm production is best at a lower temperature than your normal body temperature. If you wear compression shorts or tight underwear, spend all day sitting at a desk or even do lots of cycling, you can damage your sperm. Changing these habits can dramatically improve sperm production and DNA quality.

Talk to an Expert

Many men with high sperm DNA damage have a treatable condition. Treatment options may include medical or surgical intervention. For example, repairing a varicocele can reduce DNA damage. The same has been found for antibiotic treatment of an underlying infection. After treatment, couples can often become pregnant naturally. For the remaining men, assisted reproduction treatments like IVF may be the best pathway to having a baby. IVF success is impacted by high sperm DNA damage. In these cases, ICSI may be the more successful treatment. Fertility treatment can also be more successful if sperm DNA quality is improved beforehand.

If you would like to discuss your results with a male fertility expert, please contact us at

Consider retesting

A single test provides a snap shot of your sperm DNA quality. Men make new batches of sperm every 3 months and so DNA quality can change with time. Repeating your test after 3-6 months of lifestyle improvements or medical treatment can give you peace of mind that your sperm DNA quality has improved.

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