Usually there is no special requirement for sleeping position in early pregnancy, but avoiding lying flat in mid to late pregnancy is to prevent compression of the inferior vena cava and intrauterine oxygen deprivation of the fetus. In the early stages of pregnancy, there is usually no special requirement on the sleeping position of pregnant women, according to their own comfort and habits to take the supine position, side lying position, etc., which helps to improve the quality of sleep. It is worth noting that women in the middle and late stages of pregnancy try to avoid lying down, because at this time the uterus is increasing in size, lying down will compress the inferior vena cava, inducing low blood pressure in pregnant women, lower limb edema and so on. At the same time, lying flat in late pregnancy is also easy to increase the pressure in the uterus, is not conducive to the mother and the placenta blood circulation, thereby increasing the chances of intrauterine hypoxia of the fetus, should be taken seriously. When sleeping during pregnancy, pregnant women should not choose the prone position, in order to prevent pressure on the abdomen and chest, thus inducing dyspnea, preeclampsia and other conditions. It is recommended to develop good habits during pregnancy and create a good sleeping environment. Attention should be paid to regular medical checkups in order to monitor the growth and development of the fetus.