Clinically, it is best to wait three months after taking dental x-rays before planning a pregnancy, because x-rays have a relatively strong radiation on the human body. It takes about three months for the radiation to be completely removed. From the perspective of eugenics, it is recommended that pregnancy be considered three months after the dental x-rays are taken, and before planning a pregnancy, a physical examination is needed to understand the basic health condition of the body, as well as to understand whether the body is infected with viruses that lead to fetal malformations. An ultrasound is also needed to know the condition of the uterus and pelvis and the thickness of the uterine lining. It is recommended to start taking oral folic acid tablets in the first trimester of pregnancy in order to prevent malformations of the neural tube of the fetus and to reduce the birth of anencephalic babies as well as babies with spina bifida. Clinically, if pregnancy is planned, it is important for both men and women to take care of their health and stay away from smoking and alcohol.