Dental treatment is not recommended in the first 3 months of pregnancy because any medication and high dose of X-ray can cause miscarriage and malformation; if dental treatment must be done, it is recommended to do it in 4-6 months, but only some simple filling of cavities; dental treatment is also not recommended after 7 months of pregnancy because the fetus will compress the inferior vena cava when lying on the back for a long time during dental treatment, which will cause supine position The fetus may compress the inferior vena cava for a long time during dental treatment, which may cause hypotension, resulting in cerebral hypoxia, and thus fainting and loss of consciousness. If you really want to have dental treatment, make sure you talk to your doctor about your condition before treatment, so that your doctor will take your actual situation into consideration when treating you.