How pregnant women lie in the best position is related to pregnancy. In early pregnancy, you can freely choose the sleeping position; in the middle and late pregnancy, it is recommended to choose the left side of the sleeping position. 1. Early pregnancy: at this time the uterus is not obvious right rotation, you can choose to make their own comfortable sleeping position, generally will not affect the fetus. 2. Middle and late pregnancy: During this period the fetus gradually increases in size, especially in late pregnancy, the uterus is prone to rightward rotation, the sleeping position can choose the left side of the lying position, should avoid the supine position and lying position, in order to prevent the contraction of the uterus. It should be noted that, if you often use the left side of the lying position, you can also change the sleeping position, choose the right side of the lying position. It should be noted that in late pregnancy, you can use pillows to elevate your legs when you sleep, so as to improve the problem of lower limb edema.