BIRMINGHAM, Ala. (Ivanhoe Newswire)--The perfect male birth control contraceptive would be cheap, reliable, and reversible. It would have few side effects and would be long lasting. A new study used therapeutic ultrasound equipment in the sperm count reduction of male rats to levels which would result in infertility in humans.

Ultrasound's capabilities as a male contraceptive were first acknowledged almost 40 years ago. Although the equipment used back then is now outdated and no longer around, researchers from the Department of Pediatric at the University of North Carolina School of Medicine were able to use the experiments done as a starting point to examine whether or not modern ultrasound equipment used for physical therapy could also be used as a male contraceptive.

James Tsuruta and his team found that by rotating high frequency (3MHz) ultrasound around the testes they were able to cause steady decreases of sperm cells throughout the testes. The best results occurred two days apart while using two sessions consisting of 15 minutes ultrasound. Saline was used to provide conduction between the ultrasound transducer and skin, and the testes were warmed to 37 degrees centigrade. Combined, this reduced sperm to a Sperm Count Index of zero (3 million motile sperm per cauda epididymis).

The World Health Organization has defined oligospermia (low sperm concentration) as less than 15 million sperm per ml. Dr Tsuruta was quoted as saying, "Unlike humans, rats remain fertile even with extremely low sperm counts. However, our non-invasive ultrasound treatment reduced sperm reserves in rats far below levels normally seen in fertile men (95% of fertile men have more than 39 million sperm in their ejaculate). However further studies are required to determine how long the contraceptive effect lasts and if it is safe to use multiple times."

SOURCE: Reproductive Biology and Endocrinology, January 29, 2012