Expanding Options for Male Contraception

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.

The procedure for RISUG is similar to a vasectomy, but instead of snipping the vas deferens, a polymer that disables sperm as they pass through is injected into it. Unlike vasectomy, it is reversible and patients experience fewer side effects. Image courtesy zole4 / FreeDigitalPhotos.net

The procedure for RISUG is similar to a vasectomy, but instead of snipping the vas deferens, a polymer that disables sperm as they pass through is injected into it. Unlike vasectomy, it is reversible and patients experience fewer side effects. Image: zole4 / FreeDigitalPhotos.net

Another method that has gained some attention lately is the rather ineloquently termed RISUG — short for “Reversible Inhibition of Sperm under Guidance.” It seems to be an especially promising alternative to vasectomy, and involves the injection of a polymer gel into the vas deferens — the tube that carries sperm from inside the testicles to the urethra, through which it leaves the body. The gel is composed of styrene maleic anhydride and dimethyl sulfoxide.

RISUG is much like a vasectomy in that a local anesthetic is administered, a small incision is made in the scrotum, and the vas deferens is gently tugged out with a small pair of forceps. However, rather than being cut and cauterized, as it is in a vasectomy, the tube is injected with the polymer gel and pushed back into its place. The gel coats the inside of the vas deferens, where it remains nestled in the folds of the duct’s interior; the incision is stitched up and the process is repeated on the other side of the scrotum. RISUG seems to have fewer side effects than vasectomy — because sperm can still exit the body unimpeded, patients don’t experience the pressure or granulomas that can result from getting snipped.

The technology arose from attempts to develop water-purification systems that could kill bacteria as they passed through water pipes. A similar principle is at work in RISUG — just replace the pipes with the vas deferens and the bacteria with sperm. The polymer has a positive charge, and when negatively charged sperm pass through the polymer-lined vas deferens, the charge differential severely damages the sperms’ tails and cell membranes, as well as the acrosomes, a subunit of the sperm cell that allows sperm to be taken in by an ovum. The polymer, easily removed with an injection of sodium bicarbonate (aka baking soda — a chemical compound with a high pH), is effective for at least eight years and does not affect sperm count, libido, or erectile function. American advocates of this technology, who have given it the snappier name Vasalgel, hope to see U.S. clinical trials underway next year.

Unfortunately, pharmaceutical companies aren’t champing at the bit to roll out RISUG for American customers — a single injection lasting for years or even decades would not be very profitable. A piece in Wired magazine (fair warning: the article contains a still image of testicles and a video of the procedure) profiles Sujoy Guha, the Indian scientist who has almost single-handedly headed efforts to develop this technology despite a dearth of corporate or institutional support. His tale contains themes similar to those that pop up in the story of the Pill’s development more than half a century ago. Margaret Sanger and Katharine McCormick met similar obstacles when it came to R&D for the birth control pill in the 1950s — pharmaceutical companies didn’t think women would be interested in such a technology, so Sanger tapped the talents of scientists and the private fortune of McCormick in order to force the development of the “magic pill” she dreamed of.

It was Sanger’s vision, McCormick’s money, and the collective work of scientists that changed the lives of millions of women and families around the world. Perhaps it will take the fortunes of modern-day benefactors and the talents of independent scientists to bring us the next advancement in contraception. A grant from the Bill & Melinda Gates Foundation has already provided funding to investigate the possibilities of ultrasound, and RISUG has some stateside support from a small U.S. foundation called Parsemus.

You can find information about other technologies for male contraception currently under investigation here. However, if you’d like to learn about the forms of male contraception that are currently available to you, check out Planned Parenthood’s website.