Swelling and pain in the gums during pregnancy can be caused by diseases such as gingivitis and apical periodontitis, which need to be treated for the cause of the disease. It is recommended that patients treat the disease before continuing to take preparations for pregnancy. Avoid the problem of serious dental disease after pregnancy, but can not be completely treated. 1. Gingivitis: Swollen and painful gums during pregnancy may be caused by gingivitis. Patients need to be cleaned (scaling) to remove calculus and soft tartar, while the gingival sulcus can be rinsed with topical hydrogen peroxide solution as prescribed by the doctor. Antibacterial mouthwashes such as chlorhexidine can be used as gargles. 3. Periapical periodontitis: Gum swelling and pain during pregnancy is also considered to be caused by periapical periodontitis. If apical periodontitis occurs, root canal treatment can be taken to reduce inflammation and pain. In preparation for pregnancy, it is recommended to go to the hospital for oral examination, and thorough treatment of dental disease and scaling, to avoid all kinds of dental and periodontal diseases during pregnancy.