The vague pain in the stomach in the third trimester is mainly considered in the following two situations: 1. physiological reasons, which is a normal physiological phenomenon, as the uterus gradually becomes larger during pregnancy, the pressure on the surrounding internal organs also becomes larger, thus making the pregnant woman feel bloated and slightly painful. When the uterus grows so that the intestinal bladder is squeezed, a slight pain will appear in the lower abdomen, which will gradually ease after the body gets used to it. In the middle of pregnancy, due to the tightening of the muscles and ligaments around the uterus, the abdomen will be vaguely painful, and sometimes it will feel like spasms, this is round ligament traction pain also need not worry. The second category, pathological causes, may be habitual miscarriage, pre-eclampsia, this kind of pain will usually be accompanied by vaginal bleeding, must pay attention to it and seek medical attention in time. It may also be caused by some other diseases, such as gastrointestinal diseases, including acute gastroenteritis and urinary system diseases. Therefore, if you have abdominal pain when you are pregnant, it is recommended to go to a regular specialized hospital to improve the relevant examination and give timely and effective symptomatic treatment after a clear diagnosis.