They say that you shouldn't sleep on your back because of some artery that gets compressed but my doctor told me with every pg that you will wake up if it starts causing a problem so not to worry about it. It's not like there are a great number of positions you can sleep in while pg.

If you ever go unconscious as a pg person, the people caring for you should not lay you on your back because in that instance the artery gets compressed and an unconscious person will not wake up to adjust their position.

I have body pillows for when I sleep at night and find these help me get into a comfortable position very easily. I usually sleep on my back with the body pillow under half my body so I am slightly elevated on one side. I have two body pillows - one for either side of me because they are too hard to move in the middle of the night when I roll over.