I did remember seeing a reference to that being done in Europe. I wouldn't trust it. I did see on some TV show that it was proven that sperm count as well as sperm quality were affected. As it is now, the strongest, fastest sperm (carrying the genes of the dominant sperm in the load) gets to fertilize the egg. When test is added, suppressing natural test production and sperm production, there are fewer sperm and those that are there aparently aren't exactly what you'd call the "top of the class". I don't know what that translates to exactly if you conceive while "on", but I do know that I won't be trying it anytime soon to find out firsthand.