The causes of bitterness in the mouth of pregnant women are complicated and not exactly the same among different pregnant women. The common causes are mainly: 1. After pregnancy, due to changes in endocrine function, hormone levels change, affecting the normal digestion and emptying function of the gastrointestinal tract, resulting in bile reflux and causing symptoms of bitterness in the mouth. This symptom is a normal physiological reaction in early pregnancy and may be accompanied by loss of appetite, nausea and other symptoms, which will be relieved and disappear on its own after the third month of pregnancy. 2.Inappropriate diet, some pregnant women, during pregnancy, worry about insufficient nutrition, affecting the baby’s development and over-eating fried and deep-fried food, animal fats, various pastries, candy and other excessive intake, can also cause obvious bitter mouth symptoms. 3, the occurrence of bitter mouth symptoms are also related to bad emotions, pregnant women during pregnancy often irritable, irritable, depressed mood is also one of the common causes of bitter mouth.