Birth control options for men are currently few — but that could be about to change. New research on rats indicates that ultrasound machinery could be used to kill off sperm-growing cells, thus making males temporarily infertile.
The study on rats involved ultrasound equipment used in physical therapy. Researchers found that by rotating high-frequency ultrasound around the testes, they could kill most sperm-creating cells. The best results were seen after two 15-minutes sessions, two days apart.
Two weeks after such treatments, the sperm concentration in rats had been reduced to 3,000 motile sperm or fewer per milliliter. And while that’s still fertile for rodents, a level that low is considered infertile in humans. For us, a low sperm count is defined as anything under 15 million sperm per milliliter. A vasectomy decreases sperm concentration to 3 million sperm per milliliter.
And this technique may have uses in cats and dogs, too. Ultrasonic sterilization may be adapted to induce permanent infertility, providing a noninvasive way to sterilize household pets and control the pet population.
But for humans, researcher James Tsuruta of the University of North Carolina at Chapel Hill said in a statement more study is needed “to determine how long the contraceptive effect lasts and if it is safe to use multiple times.”
Still, the researchers write in the study published online Jan. 29 in the journal Reproductive Biology and Endocrinology, “A permanent or reversible method of contraception based on therapeutic ultrasound treatment could encourage more men to share greater responsibility for family planning.”