Men’s fertility and underwear

A more serious aspect to the inane ‘boxers-or-briefs’ question has to do with the effect of underwear on men’s fertility.  This is one of the more frequently given reasons for having switched from briefs to boxer briefs, if not boxers.  Regardless, here’s an example of the serious nature of the issue: many years ago in the days before the rise of the internet, I knew a couple that was struggling to have a baby. I’d read quite frequently that saying “if you want fruit of the womb, forget Fruit of the Loom.” Anecdotal evidence seemed to bear that old saw out; when men switched from tight fitting briefs, frequently their wives got pregnant.  So I dutifully relayed that information to the guy and lo and behold, the couple wound up having a kid shortly after he switched.  That couple’s success proved it to me.

Then things changed.  I started doubting the relationship between fertility and underwear because it simply didn’t make much sense.  Because of places I worked and research I had to do, I found that briefs were far more popular than boxers. That was based on sales data and textile industry consumer opinion studies I read and had access to; for over 50 years, almost from the invention of the men’s brief, more men wore briefs than boxers and world population grew wildly. It grew to such an extent that Paul R. Ehrlich wrote his opus The Population Bomb, warning that if we do not do something about world population, we would not be able to feed, house, or clothe the population and the world as we know it could die.

So, I asked, if underwear affects fertility, then why did the population increase to that degree?  For years thereafter, I held to the view that men’s underwear doesn’t affect fertility.  That opinion was reinforced by the famous Munkelwitz and Gilbert SUNY Stony Brook study (1998) that showed no statistically significant correlation between the style of underwear a man wears and his fertility, in terms of sperm count, semen quality, semen mobility or motility, or spermatogenesis (i.e., sperm creation).

Cut to the rise of the internet and easy, cheap information being made more widely available than before.  The old saw mentioned before became the prevailing wisdom, despite the Munkelwitz and Gilbert study.  It grew frustrating thinking that friends of mine struggling with infertility were being fed that information without any scientific basis.  And those opinions are out there even today.  So what is the current state of scientific research into the issue?  Does a man’s underwear choice affect his fertility?

My research findings

Because I believe in presenting accurate information, I actually did a search in academic databases to see if the Munkelwitz and Gilbert (1998) study results were repeated or if other studies contradict that one.  To the former question, yes, others found no correlation. To the latter, yes, many studies do contradict the Munkelwitz and Gilbert study, including several prior to their study.

ETA: Dr. Michael Eisenberg, a urologist and surgeon at Stanford University Medical Center, appears to agree that the research is inconclusive.  In fact, he says that underwear choice doesn’t matter much.

Given the mixed findings it’s unsurprising that the general consensus is that there is no general consensus.  Some studies show that anything that constricts or heats the testes, whether underwear, hot water (like a spa, hot tub, sauna, or shower), holding a laptop on a lap, or even a bike seat can negatively affect a man’s fertility. That is the actual sperm count as well as the mobility/motility of the sperm, sperm quality, and sperm generation.  In other words, heat and compression is/are bad news for your swimmers, men.

As one study put it, the findings are inconsistent (Sharpe, 2010, p. 1703).  Other studies indicate that those studies are not convincing and other factors may affect the outcome. The alternate factors include whether a man is sitting or standing (especially for long periods of time, as in sitting at work), amount of exercise, diet, caffeine use, etc. Even pollution is posited as a negative factor on men’s fertility. Apparently, abstinence also has an effect on both fertility and sperm quality, though I didn’t read the studies about that issue.  In addition, we know that psychological factors affect fertility for both men and women; it’s not entirely environmental, dietary, or physical.

The real question researchers should look into is why fertility seems to be declining in the West.  It can’t all be laid at the feet of underwear; other factors must be at play.  That is a separate issue and one that researchers are or have, in fact, looking/looked into.  In fact, some of the alternatives mentioned above are reasons for the decline (i.e., environment, diet, physical changes such as declining physical fitness and weight increase).


In short, due in part to the plethora of concomitant factors today, no one can say for certain whether underwear affects male fertility.  So the best advice probably is to give no advice.  I will anyway: if you’re a man who’s trying to impregnate his wife, then you might just want to eschew the tight drawers till you succeed. It may not help, but it can’t hurt. You might also consider exercising, losing weight, drinking less, drinking less coffee, and eating a more balanced diet. Those changes do have proven positive effects on men’s fertility.

The interesting thing is that it appears that none of these factors are permanent.  If you stop drinking coffee, after a period of time your sperm count will rise.  If you lose weight, exercise, and/or drink less alcohol, your sperm count will rise after a period of time (think of it as letting your body recover).  The same thing with your underwear choice: if you stop wearing tight underpants (boxer briefs, briefs, thongs, and jockstraps as daily underwear), after a period of time your sperm count will rise. So will motility and quality.

The only thing that appears to be permanent are health issues, such as heart disease and uncontrolled diabetes, and damage to different parts of the male reproductive system.  If you have a health issue and are trying to have children, please see your physician.  See your physician about health issues even if you’re not trying to have children.

All in all, don’t just rely on what some random guy on the internet says or what might seem to be the conventional wisdom (e.g., that briefs negatively affect fertility), check for yourself.  Question everything.  Talk to your physician.  Please.


Note about the following references: they may or may not be available on the free web. Use the doi numbers to see if you can get them free with a basic internet search (the number typically begins “10.”)

I’m providing the references for a couple of reasons.  (1) To show that I’m not just making unsubstantiated assertions.  I actually have researched the issue.  (2) To provide sources for those who are interested in the scientific answer to the question of the effect underwear has (or does not have) on male fertility.

This is not an exhaustive list regarding factors affecting male fertility. For example, I’ve left off references to abstinence and fertility.

Search terms you might consider in academic databases include: mens fertility, underwear, spermatogenesis, underwear effect on male fertility, male fertility, fertility factors, and things along those lines.  Also consider specific underwear types and ‘effect on fertility’ or ‘fertility effect.’

If you do find these articles on the free web (or through your library), look at the references each article cites for further information or articles – provided you really are interested in scientific findings related to fertility.

Jung A., Leonhardt F., Schill, W-B., & Schuppe, H-C.  (2005).  Influence of the type of undertrousers and physical activity on scrotal temperature. Human Reproduction, 20(4)1022–1027. doi:10.1093/humrep/deh697

Jung, A. & Schuppe, H. C.  (2007).  Influence of genital heat stress on semen quality in humans. Andrologia, 39(6), 203–215.

Mieusset, R., Bengoudifa, B., & Bujan, L.  (2007).  Effect of posture and clothing on
scrotal temperature in fertile men. Journal of Andrology, 28(1), 170–175.

Munkelwitz, R. & Gilbert, B. R.  (1998).  Are boxer shorts really better?  A critical analysis of the role of underwear type in male subfertility.  Journal of Urology, 160(4), 1329-1333.

Pacey, A. A., Povey, A. C., Clyma, J-A., McNamee, R., Moore, H. D., Baillie, H., & Cherry, N. M.  (2014).  Modifiable and non-modifiable risk factors for poor sperm morphology.  Human Reproduction, 29(8), 1629-1636. doi: 10.1093/humrep/deu116

Parazzini, F., Marchini, M., Luchini, L., Tozzi, L., Mezzopane, R., Fedele, L.  (1995). Tight underpants and trousers and risk of dyspermia. International Journal of Andrology, 18(3), 137–140.

Sharma, R., Biedenharn, K. R., Fedor, J. M., & Agarwal, A.  (2013).  Lifestyle factors and reproductive health: Taking control of your fertility.  Reproductive Biology and Endocrinology, 11(66).

Sharpe, R. M.  (2010).  Environmental/lifestyle effects on spermatogenesis. Philosophical Transactions of the Royal Society B, 365(1546), 1697-1712. doi:10.1098/rstb.2009.0206

Tiemessen, C. H., Evers, J. L., & Bots, R. S. (1996).  Tight-fitting underwear and sperm quality. Lancet, 347(9018), 1844–1845.


About flatpickingjd

Just your average, liberal vegetarian redneck. Yes, I'm a liberal. Proudly so. I see nothing wrong with that and wear that label with pride. Yes, I'm a vegetarian. I used to be fat, very fat. Then I started taking care of myself, lost a bunch of weight and found it easier to keep that weight off by not eating meat. Or cheese. Or eggs. Or any good stuff. Man, I miss pizza. And, yes, I'm a redneck. I like camping and fishing, listen to bluegrass music and live (from time to time) in the south(west). So, yup, I'm just your average, liberal vegetarian redneck. Serious details about me: I make my living as a lawyer. My practice focus is business law, but I've dabbled in other areas including personal injury, family law, real estate, and water law. I also hold three master's degrees with plans to earn a doctorate. I hope you enjoy your time here, and feel free to comment!
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