After 7 months of pregnancy should not lie down for a long time, try to choose the left side of the lying position to sleep, you can also occasionally change the right side of the lying position. Within the third month of pregnancy, there is no high demand for sleeping position, at this time, the embryo in the uterus is relatively small, the uterus is not obvious, lying down will not cause compression of the inferior vena cava, you can choose to sleep in the supine position, the left lateral position, the right lateral position, and try not to prone position is good. After the 7th month of pregnancy, the fetus develops faster in the uterus and the uterus enlarges more obviously, so it is OK to lie down occasionally, but try not to lie down for a long time. Lying flat will cause pressure on the inferior vena cava, which will lead to the obstruction of blood return to the inferior vena cava and reduce the amount of blood returning to the heart. Pregnant women may experience nausea, dizziness, blurred vision, vomiting and other uncomfortable symptoms. After 7 months of pregnancy, try to choose the left side of the lying position to sleep, can improve the state of the uterus right, but also to provide more adequate blood oxygen to the placenta, the left side of the lying position can be replaced by the right side of the lying position when you are tired. The above situation is not absolute, pregnant women still need to choose the appropriate position to sleep according to the individual situation.