The brain infrastructure of the fetus usually takes shape in the 4th month of pregnancy, and the brain development is basically intact at 30 weeks of pregnancy. During this period, the nervous system will gradually develop. 1. The progenitor of the brain is formed in the 1st month of pregnancy, and the first 8 weeks of pregnancy is the most important period of the development of the fetal central nervous system, which is the formation period of the brain; 2. In the 3rd month of pregnancy, the fetal brain cell development enters the first peak period, and the brain cell development is still at its peak in the 4th-5th months, and the 5th month is the proliferation period of the brain cells. At this time, the fetal auditory and visual nervous systems begin to develop gradually, brain cells are gradually complex, the fetus will interact with external stimuli as the nervous system develops, and this stage is most suitable to give the fetus good stimulation in order to form a good neural circuit; 3. 6 months of pregnancy when the surface of the brain appears grooves, 7 months perception and motor nerves are more developed, 8 months when the fetal cerebral cortex is more In the 8th month, the fetal cerebral cortex is more developed and the main sulci on the surface of the brain have basically been fully formed. In the whole pregnancy period, especially the first three months, if affected by harmful factors, often lead to children’s intellectual development disorders, so eat more vitamin-rich food during pregnancy, eat more fish, nuts food for brain.