I’m having a hard time staying on my side to sleep at night for several different reasons (pain from previous surgery on left, carpal tunnel and others on right). I wake up on my back constantly no matter what pillows or wedges I surround myself with. I know there’s mixed evidence/studies about back sleeping during late pregnancy. My question is - how far off your back do you need to be for it to be safe? Is a small wedge with a shallow angle of 15-20 degrees enough to take pressure off the vena cava?