Ultrasound used on the testicles could drastically reduce the number of sperm produced by a man, say researchers who are investigating its contraceptive potential. A study (on rats) published in the journal Reproductive Biology and Endocrinology concluded that two 15-minute doses of ultrasound could render male humans infertile. They did add, however, that lots more tests and research will be required before this could become a viable contraceptive option.
The idea of using ultrasound to induce infertility is not new. But an initial theory on the topic originating in the 1970s is now being worked on by scientists from the University of North Carolina led by Dr James Tsuruta. They won a grant from the Bill & Melinda Gates Foundation to conduct their research, and have since found out that the ultrasound contraceptive technique is most effective when it's delivered in two 15-minute doses, through warm salty water.
The experiments made the rats' sperm count drop to below 10 million per milliliter. In order to cause "sub-fertility" in male humans, the researchers said, their sperm count would need to drop below 15 million per milliliter. There got to be a catch, right? Dr Tsuruta admitted that this is only the beginning, saying that a lot more research needs to be carried out to ensure that the technique is actually safe, and reversible. The research team is not currently cure how long the effects of the "sperm zapping" last, and if the technique could be causing any long-term damage to a man's sperm. That would mean babies with birth defects could be born as a particularly nasty long-term side effect of the treatment.
For now, Dr Tsuruta and his team continue to develop this technique and to learn more about safety risks and how to eliminate this. Watch this space, though. It would certainly be great if men would have access to a reliable, long-term but not permanent, contraceptive method!