DNA damage in sperm and heat exposure

DNA damage in sperm and heat exposure

Maintaining optimal sperm health is a crucial factor for male fertility. Previous discussions have addressed the potential negative effects of tight-fitting underwear and why sitting with a laptop on your lap may be detrimental to your fertility and generally not a great idea. Today, we’ll explore another significant factor: temperature regulation.

Now, biologists from the University of Oregon have used a model organism to help identify the molecular mechanisms involved with DNA damage and how this impacts the quality of your sperm.

The Importance of Testicular Temperature

Ideally, in humans, the optimal temperature for sperm is slightly below body temperature, which is why the scrotum is located on the outside of the body. This is why, when we ask you to complete the form at the time you provide your semen sample, we ask if you have been unwell in any way – having a fever can raise your body temperature high enough to damage sperm production and impact the quality of your sperm.

Up until now, the underlying mechanisms associated with sperm damage have not been completely understood. Scientists used a species of roundworm as a biological model to observe the effects of small fluctuations in temperature and discovered that an increase of 2°C was enough to increase the level of DNA damage 25-fold. Subsequentially, eggs that were inseminated with this sperm either failed for fertilise or didn’t produce offspring.

Sperm is the smallest cell in the human body and are incredibly sensitive to increased temperatures, whereas human eggs are the largest cells in the human body and are formed internally where there the temperature is consistent. Data presented in this paper has suggested that sperm and eggs also differ in the way they control mobile DNA elements (sequences that can change position within a genome and sometimes create or reversing mutations). These DNA elements are sensitive to heat stress and when exposed to increased temperatures, these elements become mobile in developing sperm.

So, what does this mean?

The Risks of Elevated Temperatures

Essentially, this means that even a small rise in temperature can create errors within meiotic divisions and result in damaged sperm.

Fertility First offers patients the option of the Halosperm assay which is used to assess the fertility potential of sperm by determining the percentage of sperm that contain fragmented and damaged DNA. The Halosperm assay provides invaluable information about the quality of the DNA inside the sperm’s chromosomes and helps to provide clinical diagnosis and the management of male infertility.

For more information or to make an appointment contact the clinic for more details on (02) 9586 3311.

 

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FAQs about improving natural fertility

Will stress affect my ability to get pregnant?

Yes, chronic stress can impact fertility by disrupting hormonal balance and ovulation patterns. Managing stress through relaxation techniques, regular exercise, adequate sleep, and mindfulness practices may help optimise your chances of conception. Consider speaking with a counsellor if stress feels overwhelming.

How does my partner's health affect our fertility?

Sperm health accounts for about 40% of conception challenges. Your partner can improve sperm health by maintaining a healthy weight, avoiding excessive heat exposure (hot tubs, saunas, tight clothing), limiting alcohol, quitting smoking, managing stress, and taking a multivitamin with antioxidants. Sperm takes about 3 months to develop, so lifestyle changes need time to show results.

When during my cycle am I most fertile?

Your fertile window typically spans 5-6 days, ending on ovulation day. For a regular 28-day cycle, this usually falls between days 10-15, with peak fertility 1-2 days before ovulation. Track your cycle using ovulation predictor kits, basal body temperature, or cervical mucus changes to identify your unique pattern. Having intercourse every 1-2 days during this window optimises your chances.