Illustration by Stephen Savage

When it comes to family planning, tube-tying is hot, but vasectomies are not. More than twice as many married couples choose a tubal ligation for mom rather than a vasectomy for dad, according to the Center for Health Statistics-despite the fact that vasectomies are safer and cheaper. The reason, say many, is partly a yech! factor: Men simply can’t stomach the idea of someone cutting into their privates.

But Nathaniel Fried of Johns Hopkins Bayview Medical Center and his colleagues are developing a noninvasive alternative. Instead of puncturing the skin to get at the vas deferens-the tube that delivers sperm from the testis-a doctor would maneuver the tube so it’s visible through the skin and then clamp it in a stable position. The physician then would apply focused ultrasound to a specific spot and the sound waves would essentially “cook the tissue,” forming a plug, says Fried.

So far the technique has been tested only on dogs, and the researchers haven’t shown that the “plug” completely blocks the vas deferens. Also, the ultrasound can burn the skin. Fried expects to work out these bugs within two years-at which point it will be interesting to see if any men volunteer for tests.