Recent research has found that men who wear tighter fitting underwear have lower sperm concentrations than men who wear boxer shorts. To be specific, the results stated that those who wore boxer shorts had a 25% higher sperm concentration, 17% higher total sperm count and 33% more swimming sperm than those who preferred tighter underwear.
As with all studies suggesting significant statistical results, it is worth reading them with an element of scepticism. Nevertheless, it is generally accepted from numerous other studies that tight underwear may lead to reduced sperm function.
This is the largest study of its kind, with 656 male participants between the ages of 18 and 56, all of whom had visited the hospital between 2000 and 2017 as part of a couple seeking fertility treatments. Despite requiring fertility treatment, these men all had good semen quality when compared to the reference standards, ensuring reliable results. Each participant provided a semen and blood sample and was asked several questions.
The results also showed that the men who wore looser underwear had reduced levels of follicle-stimulating hormones, which takes effect to accelerate sperm production when things are going wrong and is a sign of poorer testicular health. The results of this study suggest that if men swap their underwear for something a little roomier, they might have improved sexual function.
It is worth noting that this study does not imply that a man’s choice in underwear can lead to infertility. This study doesn’t actually measure fertility; aspects of sperm quality and fertility are two separate studies. Regardless, changing the type of underwear you wear is a low cost and low risk alteration.
You might wonder what the actual link between tight underwear and sperm function is. A clue is that the testes ‘prefer’ to be two degrees cooler than normal body temperature. Note that they are outside the body rather than being kept internally such as, for instance, the ovaries. If tight underwear holds the testes against the body, their temperature tends to rise to match the body. For the same reason, our doctors caution men against taking a lot of saunas or very hot baths whilst they are trying to father a child.
If you are worried about your fertility, we would suggest booking a consultation with Concept Fertility. We can carry out tests to assess the quality of your sperm, or find another explanation for your struggle to conceive a child.