The fetal brain begins to develop at the end of week 4. The human embryo develops to the 18th day and is induced by the notochord to form the neural plate, which develops further and becomes the neural tube. The neural tube is the primordium of the central nervous system. At the end of the fourth week of embryonic development, the cephalic segment of the neural tube forms three enlarged cerebral vesicles, which are sequentially divided from anterior to posterior into the forebrain vesicle, midbrain vesicle, and rhombencephalic vesicle. The cephalic end of the forebrain vesicle eventually evolves into the two hemispheres of the brain, the caudal end forms the mesencephalon, the midbrain vesicle evolves into the midbrain, and the rhombencephalic vesicle eventually evolves into the cerebral pontine, cerebellar, and medulla. The first 8 weeks of embryonic development is the most important period of CNS development. When the embryo reaches 20 weeks of development, the brain cells proliferate, and the fetal auditory, visual and other neurological systems begin to develop slowly, and the fetus is gradually able to respond to external stimuli and make interactions. During pregnancy, pregnant women should strengthen nutrition, especially in the early stage, should be supplemented with folic acid-containing food in the first three months of pregnancy, which can help to prevent fetal neural tube malformation.