During pregnancy, the phenomenon that the belly is big on one side and small on the other is normal because the fetus appears smaller on the limb side and wider on the back side, resulting in a bigger belly side. There is also a situation where the fetus is enlarging and the uterus is also enlarging, pressing on the nearby organs and squeezing the uterus to one side, so that the uterus appears to be bigger and the other organs are smaller, making the stomach look bigger and smaller on the outside. During this period, as long as there is no special pain or uncomfortable symptoms, generally no special treatment is needed. After pregnancy, the uterus will mostly rotate to the right, so usually try to take the left side when resting, which is conducive to blood circulation.