Ultrasound Male Contraceptive

Technician operating an ultrasound device

Project Summary

Please note: This is an archived project that is not currently being updated.

Ultrasound has been proposed as a noninvasive contraceptive for men when applied to the testicles, but the effect varies greatly depending on the species and the methods applied. While ultrasound was an effective contraceptive in rats and a permanent sterilant in dogs, study results in monkeys and self-reported outcomes in humans were disappointing. We are no longer involved in research on ultrasound as a contraceptive.

Project Topics

Ultrasound effectiveness varies by species

In 2007, the Parsemus Foundation sponsored a study, conducted by Family Health International with the University of North Carolina, to test therapeutic ultrasound applied to the testes as a multi-month contraceptive in rats (reportedly 15 minutes of treatment for about 6 months of effect). This method was shown to work by one professor in the 1970’s but had never been taken seriously by other researchers until this study. The FHI/UNC team’s successful pilot study was the basis for the UNC team’s winning application for a Bill & Melinda Gates Foundation Grand Challenges Explorations grant to continue the work.

In January 2012, the results from the UNC team were published and got widespread press coverage. Here are a few examples:

Time Magazine Jan. 31, 2012
Globe and Mail
Feb. 2, 2012
Male Contraception Information Project press release Jan. 29, 2012

The Parsemus Foundation also funded an Italian team to continue their successful work on ultrasound as permanent sterilization in dogs. The results were published in 2015 and found that only one method was effective. A regimen of three applications of ultrasound at 1 MHz, and 1.5 W/cm2, lasting 5 min with an interval of 48 hours was effective as permanent sterilization in the dog without hormonal impact (get the free full text).

Raffaella pic dog ultrasound
Application of ultrasound to dog testes. Photo credit Raffaella Leoci.

Lastly, we funded an ultrasound study at the University of California, which had some effect in primates (although not as quick or long-lasting as in dogs).

Preliminary results from all three teams were presented in October 2011 as posters at the Future of Contraception Initiative conference, and the final monkey results were published here.

Vandevoort graph ultrasound
The total number of morphologically normal sperm in an ejaculate (total normal count) from male monkeys treated by two methods of ultrasound exposure. The black arrow indicates the time of ultrasound exposure. From Vandevoort & Tollner, 2012.

Effective contraception in humans remains elusive

It is now clear that under the right conditions, ultrasound works in dogs and rats (and has some effect in monkeys). However, the trick for getting long-lasting effect in large adult monkeys, and humans, has yet to be found. In fact, in late 2013 a first man decided to try ultrasound. He started with a very high personal sperm count, it is true, but it is discouraging that he found the effect of ultrasound wearing off within a few months, despite completing at least 10 treatments of 20-30 minutes on a Monday-Wednesday-Friday schedule. His results were as follows:

SPERM EVALUATIONPre-treatmentDuring treatmentRight after treatmentAfter treatment
 11/25/1412/16/131/7/142/21/14
Total Sperm Concentration62,000,00042,400,00033,400,00049,400,000
% Motility50102030
% Normal Morphology55302030
Total Sperm Count124,000,00063,600,00066,800,00098,800,000
Germinal cells0-10-10-14-6
WBC0-10-10-16-8
Pinhead ringtail0-10-100-1
Forward progression0-10-100-1

Based on the results of these studies, though, we think ultrasound has the most potential as a nonsurgical sterilization alternative for animals. Its use in humans as a six-month contraceptive remains elusive, and human use of ultrasound is complicated. Variations in the ultrasound regimen can make a big difference in effect. Even fairly short-term use in smaller animals can lead to permanent infertility, and longer term use in men appears to result in a reduction in fertility. Thus, ultrasound is probably best as a secondary method only for men who want no more children, given that there are so many questions about how long the action lasts, whether sperm are damaged and could result in abnormal offspring, and how well fertility returns.

Ultrasound has great potential as a nonsurgical hormone-sparing sterilization for dogs (a specialty item of interest to owners of large-breed dogs) as outlined in the Italian study. However, the Parsemus Foundation is not funding additional studies.

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