Male infertility is the main reason around 40% of couples seek fertility treatment. In assessing male fertility, semen analysis is the most important test. While this visit to the 'specimen collection room' is unavoidable, this initial assessment does not necessarily capture your potential for pregnancy.
Routine semen analysis will count the number of sperm and check their shape (morphology) and movement (motility), there is one thing it does not measure: DNA fragmentation.
Today I want to share with you what DNA fragmentation is, why it matters and what you can do about it!
What is Sperm DNA Fragmentation?
DNA is essentially the genetic instruction book for how we grow and function that is contained in every living cell. Breaks, or fragmentation, of the DNA will affect how the cell functions. A small amount of DNA damage is always present but when this damage is high, fertility is reduced.
If your viability is low (<50%), then it is likely that you have high DNA fragmentation rates . Even with a normal semen analysis, 15% of men can have high levels of DNA damage to the sperm.
DNA fragmentation is a major factor in unexplained infertility.
Does Sperm DNA Fragmentation Reduce Our Chance of Pregnancy?
High levels of sperm DNA fragmentation:
While semen analysis may be normal and you may have good fertilisation of your collected eggs, if you have multiple transfers that don’t implant or recurrent early pregnancy loss, DNA fragmentation may be a factor.
When a sperm with DNA damage fertilises an egg, the egg has to invest energy trying to repair the damaged DNA. If there is lots of DNA damage, the embryo won’t have enough energy to develop normally. This leads to an inability to implant or to develop further once an embryo has implanted.
In an ideal situation you want your embryo spending time growing and developing, not repairing itself from the outset!
What Causes Sperm DNA Fragmentation?
Inflammation and oxidative stress are drivers of DNA fragmentation. Inflammation and oxidative stress are elevated with poor diet, insufficient or very high levels of physical activity, stress, sleep deprivation, alcohol and chemical exposure (just to name a few).
How Can I Lower Sperm DNA Fragmentation?
One of the most potent ways to reduce sperm DNA fragmentation is by exercising regularly at optimal intensities with enough recovery.
Infertile men completing a progressive structured running program over 24 weeks had significantly reduced levels of sperm DNA fragmentation. Inflammation and oxidative stress were also significantly lower but best of all these men had a significant increase in pregnancy rate when compared to a non-exercising control group .
Structured resistance training also significantly lowers DNA fragmentation .
Where Do I Begin?
If you are exercising regularly you may want to check in with an Accredited Exercise Physiologist that your current routine is supporting optimal sperm health. The intensity, frequency and duration of your exercise sessions in combination with your strength training can be optimised for creating healthy sperm.
If you have yet to get moving, make sure you get expert advice from and an Accredited Exercise Physiologist so you can ensure you get the best prescription that is tailored for your individual needs and for making your sperm the best it can be!
Sperm takes ~72 days to be produced so changes you make now will produce healthier, happier sperm in as little as 12 weeks. It's time to get moving!
1. Samplaski, M.K., et al., The relationship between sperm viability and DNA fragmentation rates. Reprod Biol Endocrinol, 2015. 13: p. 42.
2. Maleki, B.H. and B. Tartibian, High-Intensity Exercise Training for Improving Reproductive Function in Infertile Patients: A Randomized Controlled Trial. J Obstet Gynaecol Can, 2017. 39(7): p. 545-558.
3. Hajizadeh Maleki, B. and B. Tartibian, Resistance exercise modulates male factor infertility through anti-inflammatory and antioxidative mechanisms in infertile men: A RCT. Life Sci, 2018. 203: p. 150-160.