Ultrasound

Considered on technical and practical merits alone, ultrasound is one of the most promising forms of male contraception. It is technically simple and extremely convenient in that ten minutes of ultrasound results in six months of sterility, and it requires less dedication than methods such as artificial cryptorchidism and wet heat. In contrast, the task of addressing users' (and policymakers') concerns has been more difficult than for other methods (Wilmore, 1988).

For ultrasound contraception, ultrasound waves (very short, inaudible sound waves) are used to heat the testes. The ultrasound waves are of the same type and intensity as those used by physical therapists to treat injuries.

To use the method, a man first sits in a special chair with his scrotum in a cup of water. In the bottom of the cup is an ultrasound element, which heats the water about as hot as a hot tub. It has also been hypothesized that the ultrasound creates an ion exchange between the fluid in the seminiferous tubules and the rete testis, making the environment in the testes inhospitable for sperm formation (Fahim et al., 1977). The method is painless. Some men even report the procedure to be pleasurable.

After five to ten minutes of ultrasound, six months of infertility results. With two treatments 48 hours apart, ten or more months of infertility will result (Fahim, 1980). Fertility returns gradually once the infertile months are over.

The most important priority for research is the question of whether, and how, fertility returns after multiple uses of the method (Kandeel & Swerdloff, 1988). For example, could a man safely rely on ultrasound for contraception for five to 15 years? It is also important to confirm the results of previous safety studies. Ideally, researchers would begin this testing process now.

When a new contraceptive is introduced, it is standard practice to approve it for several years’ use and then extend the approval as long-term data on the original study subjects becomes available. As was done with contraceptives such as the Mirena, researchers should begin tests now so that longer and longer uses of ultrasound can gradually be approved (or not approved, as the case may be).

Unfortunately this is not happening. The only researcher who has published extensively on ultrasound contraception is the late Dr. Mostafa S. Fahim, Director of the Center for Reproductive Science and Technology at the University of Missouri at Columbia. In a study of the comparative contraceptive effects of heat, ultrasound, infrared rays, and microwave rays, Dr. Fahim found ultrasound to be the safest and most effective (Fahim et al., 1975). He carried out the first definitive studies on the method of action of ultrasound and its genetic safety in future generations of animals (Fahim, 1980). He secured patents on the concept of ultrasonic contraception (both for humans and for sterilizing pets) and the equipment used to accomplish it (Fahim, 1978a, 1978b).

One would think that with so much investment in the idea, Dr. Fahim would have continued actively researching ultrasound and working to build the mass of data needed for its acceptance. Yet although Dr. Fahim collaborated with Chinese researchers on using longer and higher doses of ultrasound for permanent sterilization and on using ultrasound to treat epididymal pain and swelling after vasectomy, in 1980 he stopped research on ultrasound as temporary contraception. The reasons included limited funding and strict restrictions on who could participate in his first human trials (Corea, 1985, ch. 9). Due to these and other constraints, Fahim moved on to other areas of research.

Many researchers doubt Dr. Fahim's results, partly because a 1988 paper seemed to contradict them (Urry et al., 1988). However, although the study was published in 1988, it actually reported on a study conducted in 1973-76, before many details of Dr. Fahim 's technique were available. It is thus not directly comparable.

As is so often true for innovative and creative researchers, Dr. Fahim received little respect or recognition during his lifetime. He passed away in 1995 and did not live to see the day in 2003, after almost 20 years of work by his team, that the FDA approved his injectable sterilant for dogs (Friedman, 2003). This nonsurgical sterilant is not appropriate for humans because it reduces testosterone levels, but it is likely to have a huge impact on the pet overpopulation problem. The dedication of his family, his fellow researchers, and his financial backers to the development of this sterilant is a testament to their belief in the importance and promise of his idea.

So with one of Dr. Fahim ’s ideas now on the market, and with cheap sperm tests now available over the counter, has ultrasound’s time finally come? Dr. Min Wang, a senior research associate at the Center for Reproductive Science and Technology at the University of Missouri-Columbia and a close collaborator with Dr. Fahim, says ultrasound is still “basically a good idea” scientifically. He points out that localized methods such as ultrasound are less prone to side effects than hormonal methods (personal communication, M. Wang , November 9, 2005). However, he says, ultrasound is not likely to be developed because at this point “every technology has to have a company behind it” to pay for the clinical trials and the FDA approval process. Ultrasound contraception, unlike the Neutersol sterilant, is not a moneymaker that will attract investors. Unless the public pushes for government- and foundation-sponsored research, ultrasound contraception will have no future.

Next section: Oral Methods of Male Contraception