Trying for a baby? Fertility experts warn against heated blankets and seat warmers as temperatures drop

Male infertility is a rising problem with global sperm concentration halving in the last 40 years. This has led to science devoting more time and resources to exposing the problem. While it’s long been suspected that heat can affect male fertility, we now understand more of the reasons behind the correlation.

With temperatures dropping and energy bills across the UK increasing, many will be looking for alternative ways to keep warm this winter. However, there are some forms of direct heat you may need to avoid during the colder months, particularly if you’re trying to conceive.

The experts at Fertility Family share their insights below.

Avoid using car seat warmers

In the winter, cars can take some time to warm up properly. But car seat warmers remedy that, warming you up in very little time.

However, your testicles are right in the firing line of this heat. So, particularly when you’re trying to conceive, try to avoid regular use of seat warmers and instead pop on an extra layer.

Avoid putting heated blankets directly on your lap for long periods

With temperatures decreasing and more time spent in the house, you might not even notice that you’ve been sitting with a heated blanket on your lap for hours. However, these generate significant heat. And, since it’s a heat source that can stay there for hours at a time, heated blankets can pose a problem for male fertility.

It’s also important to consider that when sat down for long periods with your legs close together, the position will also raise the temperature of the testes, again negatively impacting fertility.

Wrap up, but don’t wear tight-fitting pants or underwear

Whilst we encourage you to wrap up during the colder months, we’d recommend avoiding any tight-fitting underwear underneath your layers.

The danger here is your testicles being pushed too close together, as they would be when your thighs are together for long periods. The resulting increase in testicular temperature ranges from 0.5C to 0.8C.

Although this might not sound like a lot, sperm needs optimum conditions to thrive and help you conceive. So, if wearing looser underwear can make even a small difference to your sperm’s health, it’s a change worth making.

How does heat affect sperm concentration and motility?

In short, heat – whatever the source – causes oxidative stress and harms sperm concentration and motility. So, not only does it impair your body’s ability to produce sperm, but the sperm it does produce has a harder time swimming to reach and fertilise an egg.

Lower concentrations of sperm and lower sperm motility are common infertility symptoms and can drastically affect your chances of starting a family.

Avoiding sources of direct heat to your testicles is just one thing to consider when trying to conceive. This alongside taking a supplement like Impryl to improve sperm quality, following a balanced diet and getting regular exercise, are some lifestyle changes that can help to improve male fertility significantly.

Terry Sullivan, Founder and Managing Director of Fertility Family says: "For healthy sperm, the ideal temperature is around 35°C, which is about 2°C lower than body temperature. Even small temperature increases can inhibit spermatogenesis and cause infertility. One study (Durairajanayagam D, Agarwal A, Ong C. (2015)) found each 1°C increase in testicular temperature caused a 14% decrease in sperm production. The use of heated seats can increase the scrotal temperature to around 37°C, causing a significant enough increase to impair sperm production. Prolonged exposure to heat, whether it be from heated blankets, saunas, or heated seats, has the potential to adversely affect male fertility."