Sleeping on your back: When you sleep on your back it could cause problems with backaches,vreathing, the digestive system, hemorrhoids, low blood pressure and cause a decrease in circulation to your heart and to your baby. It could result of your growing abdomen resting on your intestines and major blood vessels. You could also develop sleep apnea as you gain weight.

Sleeping on your stomach: While you are farther along in your pregnancy, your vreasts be ome more tender and your abdomen continues to grow, both making sleeping on your tummy uncomfortable. Using a donut shaped pillow could help you sleep comfortably on your stomach.

Reasons for your discomfort includes:

During pregnancy, you would find yourself wrestling in bed trying to feel comfortable before falling asleep. When you are pregnant your body will go through a variety of changes which causes your regular sleeping positions to no longer work for you.

• Increased size of the abdomen

• Back pain

• Heartburn

• Shortness of breath

• Insomnia

Source: https://americanpregnancy.org/healthy-pregnancy/pregnancy-health-wellness/sleeping-positions-while-pregnant/