Generally speaking, in early and mid-pregnancy, you can sleep flat on your back, and in late pregnancy, it is recommended that you lie on your side, either on the left or the right side. In early and mid-pregnancy, although the uterus has also increased in size, generally does not compress the inferior vena cava, at this time the pregnant woman can lie flat to sleep, but also can choose their own suitable position to sleep. In late pregnancy, when lying down, the enlarged uterus will compress the inferior vena cava, causing supine hypotension, thus affecting the blood flow of the umbilical artery, so it is not recommended to lie down, you can lie down on the side, the left side of the lying position or the right side of the lying position can be. Pregnant women should follow the doctor’s instructions on time obstetric examination, can early prevention and treatment of pregnancy complications and comorbidities, timely detection of fetal anomalies, and can assess the situation of pregnant women and fetuses, to ensure the safety of mothers and infants. Also under the guidance of the doctor to improve the diet to ensure that the intake of adequate nutrition to meet the physiological needs of the mother and fetus.