I think it often depends on the reason for the PPH. I had one with my firstborn, but it was because the cord had detached from the placent befor the placenta could be delivered - and that only happened because the cord had formed on the very edge of the placenta (which is highly unusual). So the liklihood of a repeat in circumstances is highly unlikely.

Maybe you should have a chat with you doctor the next time you go in and see what they say. Certainly, if there are extra risks, they could take steps to minimize these risks, and handle any situation that might occur.