Condoms are the only contraceptive device that does double duty in preventing pregnancy and STD transmission. But will men’s birth-control options expand?

Many have wondered why there is not a male equivalent to the Pill. The short answer to this question is that the release of one egg is easier to prevent than the flow of millions of sperm. The longer answer to that question includes a litany of failures in the search for such technology. Currently, however, there are some interesting developments in male birth control.

The condom, of course, is the only birth-control method to do double duty in reducing risk for both pregnancy and STD transmission, but many heterosexually active males would like more options than the tried-and-true rubber, and their female partners, despite having expanded contraceptive options — including the Pill, the patch, and the IUD — might prefer for the men in their lives to help shoulder the birth-control burden.

One method under investigation is ultrasound, a technology that has been around for quite some time. Though scientists have been aware of its contraceptive potential since at least the 1970s, most studies have been conducted on nonhuman animals (though human trials could be on the horizon). Ultrasound involves the application of high-frequency sound waves to animal tissue, which can absorb the sound waves’ energy as heat. The possibility for ultrasound’s use for contraception operates on the idea that briefly heating the testes, which in mammals are normally kept a few degrees below core body temperature, can halt sperm production, leading to temporary infertility for about six months. Additionally, ultrasound could affect cells’ absorption rates of ions, which itself could create an environment unfavorable to spermatogenesis. Its extremely localized effects on animal tissues make ultrasound an attractive candidate for research.

One small study conducted on five dogs applied ultrasound to the canine testicles three times over a period of a few days. The researchers compared sperm count before the procedure to two weeks after the procedure. After the ultrasound treatments none of the canine sperm samples contained sperm. Side effects included tender testicles that had been reduced in volume. Continue reading →