Why do you need oral examination before pregnancy, many common diseases during pregnancy are related to oral diseases, to ensure dental health, is one of the prerequisites to safely through pregnancy, accept oral health is the key. The following checks should be carried out: 1, for the treatment of gingivitis and periodontitis, the rise in hormone levels in the female body after pregnancy will lead to an increase in vascular permeability of the gums, gingivitis is prone to occur, and some will be aggravated before pregnancy. 2, the treatment of tooth decay, easy to aggravate during pregnancy, once the outbreak of acute pulpitis or apical inflammation, it will bring unbearable pain, the use of medication is not good for the fetus, the treatment of their own and the fetus are beneficial . 3.Wisdom teeth pericoronitis: it is easy to happen between 20-35 years old, should take out the blocked wisdom teeth before pregnancy.