Everyone seems to think that wearing briefs reduces a man’s sperm count and that wearing boxer shorts improves the sperm count. Everyone but medical researchers, that is. Sperm counts are not affected by whether the man wears briefs or boxer shorts.

The only exhaustive or conclusive study on the subject showed that there is no negative impact of briefs on sperm count. The researchers concluded that ".. male underwear choice is associated with few differences in semen parameters; no association with time-to-pregnancy is observed providing reassurance to couples attempting pregnancy.." Just to be sure, doctors still recommend that men who want to conceive should wear loose-fitting underwear or no underwear at all, but there is truly no research that has confirmed this.

The research

The theory that male infertility can be caused by wearing briefs comes from a misunderstanding about one of the legitimate causes of male infertility. Studies have shown that prolonged exposure of the testicles to high heat can affect sperm production and quality.

One study of 50 men at Liebig University in Germany found significantly higher scrotal temperatures in men who wore jockey shorts than in those who wore briefs, and the lowest scrotal temperatures in those who wore no underwear at all. Another study, published by the Journal of Urology, measured scrotal temperature in 97 men and found no discernable difference in temperature between men who wore tight underwear and those who did not.

But that does not apply that this research impacts sperm count for men wearing briefs as opposed to wearing boxer or no shorts. There were studies done that researched whether briefs or boxers impact the sperm count. These studies have shown that briefs do not have a negative effect on sperm counts. The heat generated by wearing briefs isn’t significant enough to have a negative impact on sperm production. On the other hand, soaking all day in a hot tub might cause fertility trouble for a man, but wearing boxers instead of briefs isn’t going to make a difference.

Male infertility either alone or together with a woman's problems is responsible for about 50% of all known infertility issues.

Sperm and body temperature

The normal volume of semen ranges from 1.5 to 5.0 milliliters per ejaculation, according to the National Library of Medicine. Typically, semen contains 20 to 150 million sperm per milliliter. To be effective, at least 60 percent of sperm should have a normal shape and ability to move forward, known as motility. Very low or very high sperm counts reduce fertility.

A man’s testes produce sperm; his body stores sperm in the epididymis, which lies on top of each testicle. In order to produce sperm, the testes must be cooler than the core body temperature. Briefs hold the testes close to the body, where they may become too warm to produce sperm effectively; low sperm counts may ensue.

Other causes of low sperm count

The use of alcohol, tobacco, some prescription drugs, and many recreational drugs may also lower sperm counts. Men should be aware that it takes 10 to 11 weeks for their bodies to produce sperm, so any measure to increase sperm count should begin weeks before attempts to conceive.

Partners who are having trouble conceiving should each undergo medical testing to determine the cause of infertility. A doctor or reproduction specialist will perform a thorough evaluation, order a semen analysis to measure sperm count, and provide information on fertility treatments.