I've had 3 chicks pip upside down in their shells. I then open the shell just enough so I can remove the membranes around their noses so they have a clear path to air. There's been a fair share of blood each time, but after opening the shell to ensure they can breath, I leave them like that for about 8 hours and then go back and unzip the shells for them and by that point, most/all of the blood is absorbed and they pop right out healthy as can be. I then put them back in the incubator with their butts still in the shell and let them continue to absorb anything else they need to and then let them seperate from the egg. Works great. But what causes chicks to get turned upside down in the first place?