Birth Control for Men? Zap Testicles With a Dose of Ultrasound Heat

Has the answer to a quick, painless, reversible male contraceptive been in doctors' offices and commercially available for decades? One study says yes.

Therapeutic ultrasounds machines, which are currently used to relieve injured joints with heat, according to the study by the University of North Carolina-Chapel Hill researchers, could someday be a viable form of contraceptives for men. According to the press release, the researchers were able to reduce sperm counts for a long period of time -- two and a half months -- in rats by giving the rodents' testicles just two 15 minute doses of the ultrasound heat.

Here's how the treatment works:

The best results came from undergoing two sessions, each consisting of 15 minutes of ultrasound, two days apart. During the sessions, the testes were placed in a cup of saline to provide conduction between the ultrasound transducer and skin.

The researchers were not able to continue their study for long enough to see when, or whether, fertility would return. But they knew it was effective: microscopic examination showed dramatic changes after just two weeks. Normally, testes are full of many layers of cells developing into sperm, but now the tubes of the testis were almost empty. "Sperm production is very robust; this ensures the survival of a species. It's really difficult to find a way to turn off the production of sperm, but ultrasound seems to do the trick," Dr. [James] Tsuruta [said]. "There is something special about heating with ultrasound — it caused 10-times lower sperm counts than just applying heat."

A different set of researchers showed that this technique also worked in primates -- and was reversible. Dr. Catherine VandeVoort from the University of California-Davis who led the primate study spoke about the slightly awkward research they had to conduct to see if it would work in the monkeys:

"The monkeys didn't seem to mind the treatment a bit, but we were having a rough time of it. Thirty minutes of treatment three times a week is a lot of monkey testicular massage. We felt pretty silly, and it didn't help when the techs would come around and wonder what kind of research we were doing! We were relieved when we finally saw an effect."

A third set of researchers in Italy tested the technique on dogs in the hopes of permanent sterilization to reduce the stray dog population. The press release states that using five doses of the therapy on the dogs did achieve permanent sterility, leading researchers to consider this as an alternative to surgical vasectomies.

It also leads some to be cautious about using ultrasound as a temporary form of birth control: there is a risk for permanent sterilization; couples have no definite way knowing when sperm counts would come back up again; and there could be potential effects on sperm structure that could lead to a damaged embryo:

"This is an interesting development in a challenging indication," says regulatory consultant Gary Gamerman of Seraphim Life Sciences. Though much remains to be done, there's nothing inherent to the method that would make ultrasound dead in the water from a regulatory standpoint. "The only concern is proof of safety and durability of response. As long as it prevents fertile sperm, is overall safe and doesn't cause secondary safety or adverse sexual effects, there wouldn't necessarily be anything that would hold it back. You just have to do the studies."

Clearly, more studies would need to be done before this is considered as a permanent or temporary form of contraceptive for men. But as New Male Contraception's website states, "there is nothing preventing men from buying a $1,300 ultrasound machine online and trying it."

[H/T Popular Science]