Before pregnancy is required to do oral examination, the prospective pregnant mother in the regular hospital dentistry for a comprehensive oral examination and oral health care before pregnancy, thorough treatment of oral diseases to eliminate worries, understand the basic knowledge of oral health care, reduce the occurrence of dental disease during pregnancy or prevent the further development of the disease. The dentist can give guidance to the pregnant mother on oral care during pregnancy, and the items to be examined are: 1) check whether the oral cavity is clean, whether the gums are red and swollen or even bleeding, if there is such a phenomenon, the corresponding systemic treatment should be done, such as periodontal cleaning, which is also known as scaling and other oral care; 2) whether there is caries, if there is caries, timely filling treatment should be carried out; 3) whether there are residual roots, crowns and recurrent inflammation in the oral cavity that should be extracted If there are wisdom teeth, if there are any, they should be extracted in time to avoid acute attack during pregnancy; 4.Remove bad prosthesis, i.e. dentures, and repair them; 5.Check whether there are missing teeth, if there are, they should be inserted in time to restore chewing function. It is necessary to understand the basic knowledge of oral health care, to reduce the occurrence of dental diseases during pregnancy, to stop the further development of the disease, to help pregnant mothers master the knowledge of self oral care, and to improve their oral health.