I try so hard not to turn on my back in my sleep but I can never stay on my left side! I wake up with my stomach hurting so bad! 😫
the side affects should wake you up if somehow you end up on your back. you'll feel nauseous long before it affects baby.
baby puts pressure on the major blood vessel.. Thats usually only the second half of your pregnancy though, when it could cause problems. you'll feel the adverse affects like dizziness, short of breath, & nausea. depends on where baby is positioned too.
I always find myself on my back during the night, I just can't get comfortable on my side.