It is generally recommended for pregnant women to avoid sleeping on their backs, especially in later stages of pregnancy. This is because the weight of the uterus can compress major blood vessels, potentially reducing blood flow and oxygen supply to both the mother and the baby. However, it is important to note that every woman's body is different, and some may not experience any issues while sleeping on their backs. The best position for sleep during pregnancy is usually lying on your side, preferably the left side, as this helps improve circulation and ensures optimal blood flow to the placenta. Placing a pillow between your legs or under your belly can provide additional support and comfort. If you find it difficult to stay in one position throughout the night, using multiple pillows or investing in a pregnancy pillow can help you maintain a comfortable and safe sleep posture. It's always best to consult with your healthcare provider for personalized advice based on your specific circumstances.