Pregnancy vomiting disappears on its own in the third trimester, when the placenta is fully formed and secretes the estrogen and progesterone needed for pregnancy. After pregnancy, because the estrogen in the body increases thousands of times, this will cause water and sodium retention, and at this time the gastric mucosa will become edematous, so nausea and vomiting will occur, and there will be more saliva and clinical manifestations of anorexia. In addition, due to the increase of estrogen, there will be a mild enlargement of the breast and the nipple areola will suffer. The anterior uterus will also cause the bladder to store less urine and cause frequent and urgent urination. After the third trimester, the uterus rises from the pelvic cavity to the abdominal cavity, so that the bladder is not compressed and the symptoms of frequent and urgent urination disappear.