Anencephaly is a type of fetal neural tube malformation, a serious lethal abnormality, and once detected mid-pregnancy induction of labor and abandonment of the fetus should be given. The cause of anencephaly is unknown. It is usually related to the development of the fetus itself, where abnormalities occur during the chromosome formation stage, leading to abnormal development and the formation of anencephaly. Of course, sometimes it is also related to the external environment, such as when a woman receives more intense radiation during early pregnancy, but this is very rare. Most of the anencephalic babies are still caused by the abnormal development of the fetus itself, which has nothing much to do with the mother or the environment. Once the anencephalic babies appear, they usually have to be induced in the middle of pregnancy to give up the fetus.