Male contraceptive advice: just wear a polyester sling, and let the heat and the electrostatics do all the work

Hey, it's science! 

So, is birth control just a women’s issue? Men are equally involved in producing a baby, and there are a few male-centric birth control options (i.e., condoms) available. But there’s definitely room for new male contraceptives–especially ones that aren’t permanent and don’t require last-minute application. And that’s where the polyester comes in. 

No, not this kind of sling, dummy.

Apparently, simply wearing a polyester sling (I suppose you could get one that isn't polyester, and line it yourself) around the scrotum can produce sperm-free semen (azoospermia), presumably from the heat (what’s sweatier than polyester?) and the electrostatics. The sling must be worn for months before it’s effective, and it takes another couple of months, after removal, to reverse the effects.

This makes sense, if you give it any thought (which I never have) because your balls hang low for more than one reason, and one of those reasons is temperature regulation. In order for sperm to mature successfully, they need to be kept a few degrees lower than normal body temperature, so keeping them below the body is a good way to keep things cool. 

Related stuff: 

Swinging high and low: Why do the testes hang at different levels? A theory on surface area and thermoregulation. 

and this:

Scrotal Asymmetry In Man And Ancient Sculpture which discusses the fact (?) that the left side generally seems to hang lower. 

Previous studies in dogs wearing polyester underpants showed that the dogs had reduced sperm count under those conditions:

"A recent study has shown that dogs, while wearing polyester underpants, had a diminished sperm count which was reversible when the pants were removed. In contrast, dogs wearing cotton pants showed insignificant semen changes.”

Here's the abstract from the paper on humans mentioned back at the beginning of this post (I don't, unfortunately, have a link to the dog paper), which, by the way, also fits into the "tax dollars at work" category, since it's from the NIH:

Contraceptive efficacy of polyester-induced azoospermia in normal men.

"Every 2 weeks, a physician at the Faculty of Medicine at Cairo University in Egypt examined 14 32-47 year old male volunteers wearing a polyester scrotal sling day and night for 12 months to determine if polyester fabrics can act as a contraceptive in men. 

They changed the sling only when it became dirty. None of the men dropped out of the study. The sling did not cause any complications or reactions. Their partners took an oral contraceptive until 3 sperm samples proved the men to be azoospermic. The men became azoospermic from 120-160 days (mean 139.6 days) after 1st putting on the sling. They remained azoospermic throughout the study. None of the partners became pregnant during the study. All 5 couples who wanted a pregnancy after the study period did indeed conceive. 4 had normal live births and 1 a miscarriage. The volume of their testicles fell greatly from 22.2-18.6 sd ml during the 12 months (p.05), but returned to pretest levels 75-135 days after removal. Further the mean rectal-testicular temperature difference was lower 3 months after wearing the sling than it was before they wore it (1.3-3 degrees Celsius; p.001). 3 months after they stopped wearing the sling, the mean rectal-testicular temperature difference reverted to normal. 

The polyester in the sling generated greater electrostatic potentials during the day than at night (326-395 volt/sq. cm. vs. 142-188 volt/sq. cm.; p.01). This was a result of the friction between the scrotum and the polyester sling. Germ cells of the seminiferous tubules still exhibited degenerative changes 6 months after removal of the sling. Within 140-170 days after removal, sperm concentration levels returned to pretest levels (40 million/ml). Apparently the electrostatic field effect and the disordered thermoregulatory effect of the polyester sling produced azoospermia. In conclusion, the sling is a safe, acceptable, inexpensive, and reversible method of contraception in men.”

Borat's mankini might work

 for this purpose

Somewhere in reading about this stuff I ran across this (read the whole thing), on the dangers of blogging (if you're male, that is):

When bloggers write, with laptops, seated,

Bits of them get overheated—

Sitting in their rooms, retreated

To their hidden cloisters.

If I should hear “Well done! Well done!”

I hope they mean my writing’s fun

And not some cruel and heartless pun

About my mountain oysters.

That reminded me of the Family Guy episode "Hell Comes to Quahog" (I couldn't find it on youtube), which is the episode in which Superstore comes to town. It's just after Peter gets a job at Superstore :

Peter: Boy Meg, I am so looking forward to this job. 

Brian: Peter, I can't believe you're working for Superstore USA. How could you sell out like that? 

Peter: Because Brian, they have industrial sized air conditioning. And I'm tired of sitting in ball soup.

And, of course, it's impossible to touch on this subject without including Monty Python's classic Every Sperm is Sacred skit from The Meaning Of Life:

Related post:  

The Great Sperm Race: The Most Extreme Race on Earth. Scaled To Human Size (plus bonus Monty Python)

More at Discover, Scitopia and ScienceBlogs.