Researchers also must keep the safety of the sperm in mind. If the technique did not eradicate sperm entirely, or if the sperm recovers down the road, in, say, six months, conception is possible and the risk of birth defects and genetic anomalies in the fetus would become a concern.
About 26 percent of U.S. men use one method or another to control fertility, including vasectomies and condoms.
Even though about 70 percent of U.S. couples use some form of contraception, an estimated one million pregnancies end in abortion each year in the U.S. About half of all pregnancies are mistimed or unwanted, and Tsuruta, an assistant professor of pediatrics, said he believes that every child who is born should be wanted.
"The most direct path to reducing the rate of unwanted or mistimed pregnancies is to have women and men sharing responsibility for family planning," said Tsuruta. "One of the goals of research in male birth control is to provide men with more options for controlling their fertility. "We are planning studies on rats to work out issues of safety, reliability and reversibility, before testing the method on men. Safety is paramount."
Despite the potential experts see in the zap, there is still much to be learned about the procedure and any new, widely-available contraception method using the technology is probably a long time away.
"I wouldn't expect a 'scrotal boombox' to hit stores any time soon," Terlecki said.