Vomiting and stomach discomfort in 39 weeks of pregnancy may be caused by indigestion, acute fatty liver in pregnancy, liver injury in pregnancy, HELLP syndrome and other causes. 1. indigestion: at 39 weeks of pregnancy, the uterine fundus has reached the umbilicus and the xiphoid process, so that the stomach and intestinal tube upward displacement, when eating too much food due to indigestion can cause nausea, vomiting and stomach discomfort, combined with the history and clinical manifestations can assist in the diagnosis. 2. Acute fatty liver in pregnancy: mostly occurs in late pregnancy, mainly manifested by persistent gastrointestinal symptoms, such as nausea, vomiting, epigastric pain and progressive jaundice, etc. Combined with clinical manifestations, liver and renal function, the diagnosis can be made. Combination of clinical manifestations, liver and kidney function, coagulation function, blood routine, liver and gallbladder ultrasound can help diagnosis. 3. Liver injury during pregnancy: it may also cause gastrointestinal symptoms such as nausea, vomiting and gastric discomfort, etc. Liver function test suggests elevated aminotransferase, blood routine and coagulation function are normal, which can help to diagnose the disease by combining with the clinical manifestations and laboratory tests. 4. HELLP syndrome: also cause nausea, vomiting, right upper abdomen or epigastric pain and other symptoms, there is a history of preeclampsia, combined with the history, clinical manifestations and blood routine, coagulation function, liver and kidney function, cardiac enzyme spectrum and other tests can assist in the diagnosis. Vomiting upset stomach in 39 weeks of pregnancy requires prompt hospitalization to identify the cause and actively deal with it.