Sleeping on Back?

[MantaRay]

The problem, as the others have said, is that your main artery running down your spine can get compressed. When this happens, your bp will drop dramatically and therefore so will the babies. Usually you will become aware of it quickly, but it is much better to not have it happen in the first place. You only need to be on a 10 deg angle to prevent this, so the best option is to place a pillow down behind you so that if you roll over onto your back, you are tilted by the pillow.

[Mellbell]

Thanks for that - i will give that a shot!