After pregnancy, the belly of a pregnant woman is gradually enlarged. Usually, during the first 3 months, the uterus enlarges in the pelvic cavity and there is no visible manifestation of the abdomen at this time. As the saying goes, in the 3rd trimester, the uterus expands and grows out of the pelvic cavity into the abdominal cavity around the 12th week of pregnancy. At this time, the pregnant woman’s abdomen will appear to slowly expand, and by the 4th to 5th month of pregnancy, the bottom of the uterus will basically grow to the navel. At this time, the lower and middle abdomen is bulging and the outline of the uterus can be clearly felt. In the 7th and 8th months of pregnancy, the uterus gradually increases in size and grows to a position between the navel and the saber process. At this time, the pregnant woman’s belly is bulging and she feels that she is eating less because of the slow peristaltic movement, and sometimes she breathes faster or takes deep breaths. After the fetal head is in the pelvis at about 9 and a half months, the pregnant woman will experience a significant sense of relief. After the fetal head is in the pelvis, the bottom of the uterus will drop, and at this time, pregnant women can eat more than before and breathe easier than before. Therefore, the pregnant woman’s belly is gradually expanding throughout the pregnancy, and the degree of expansion varies according to the month.