The size of a pregnant woman’s belly varies from person to person, depending on each person’s situation. If you are a fat person, your belly must be bigger, because the fat layer is thicker, so it looks bigger than the normal pregnancy week. If you are a thin person, your stomach must be smaller, but as long as the fetus is growing and developing normally and the pregnant woman herself has no abnormalities, this will not be affected during the whole pregnancy. People also often say that the first and second trimesters are relatively larger and the second trimesters are relatively smaller, but these are all appearances and lack scientific basis. The main clinical data to monitor are the fundal height and length of the uterus to estimate the size of the fetus and the number of weeks of pregnancy. In the fourth month of pregnancy, the height of the fundus should be between the pubic symphysis and the belly button. The length of the uterus is not measured clinically because the fetus is still relatively small at this time. The length of the uterus and the abdominal circumference of the pregnant woman are usually measured routinely in the fifth month of pregnancy, that is, at 20 weeks of gestation, and the next maternity checkups are also routinely measured, because this is the time when it is more meaningful. In fact, the size of the belly is not the focus of the pregnancy, the focus is on the growth and development of the fetus and the indicators of the pregnant woman are normal.