I asked my public health nurse this question and she said it is ideal for blood flow to your body and to the baby. Even breathing can be better when laying on your left side! Pregnant or not it's good! That's why if you are ever having contractions or pains drinking water and laying on your left side is recommended!
cuz if u lay on your back you will wake up with the worst back pain and laying on ta side is better for blood flow and breathing.
they say it's because it helps with blood circulation and breathing
people say it's better but for me if I lay on my left side to long it's goes numb some I have to alternate sides.
blood circulation is better for you && baby
sleeping on your left side allows for good blood circulation and increases oxygen flow. laying on your back after about 16 weeks is not recommended because the weight of your uterus and the the baby presses on your other organs causinf decresed oxygen and blood flow and other problems.