The left side of the stomach pain in the third trimester of pregnancy to consider whether it is caused by personal fetal gas, there may also be chronic gastroenteritis, lymphadenitis or signs of fetal dysplasia, miscarriage, but also because of unintentional twisting caused by the specific circumstances of the case and then do the treatment. If this happens, you should go to the hospital for a progesterone test, a gynecological ultrasound, and determine whether it is caused by a miscarriage or other illnesses based on the presence or absence of vaginal bleeding. If it is accompanied by vaginal bleeding, it should be treated with fertility preservation, intramuscular injection of progesterone and bed rest. If it is caused by gastritis or gastroenteritis, pay attention to the regularity of life, prohibit spicy and stimulating food, and pay attention to keep the abdomen warm. If it is simple stomach pain, you can keep your abdomen warm. During pregnancy, keep your mood happy, anger and depression can also cause stomach pain.