The reason for this is: 1. The hormone level in the body is disturbed after pregnancy, resulting in increased secretion of the oral mucosa and increased saliva. 2. After pregnancy, women need to provide nutrition to the fetus, the metabolism in the body will accelerate the secretion of the glands will increase, and pregnant women will feel that the saliva in the mouth is constantly produced. 3. The problem of vomiting and acid reflux will occur due to the increase in the level of luteinizing, and the acidic gastric juices will stimulate the mucous membrane, resulting in increased secretion of glands and increased natural saliva. 4, pregnant women with oral inflammation, local inflammation will stimulate the mucous membrane, so that the mucous membrane secretion increases saliva constantly. The problem of increased saliva will generally be relieved by itself after 3 months, and some may be relieved in 4 months. During pregnancy, you need to exclude the possibility of oral inflammation and pay attention to the cleaning of the mouth to avoid causing mouth ulcers during pregnancy.