Children with Down’s syndrome usually have physical and mental defects, and at six months of age, they also have developmental delays and behavioral disorders. 1. Physical defects: wide eye spacing, small eye cracks, double inner canthus, outer canthus upward, low nasal bridge, narrow hard palate, often salivating, short and wide neck. 2. Intellectual defects: there are mild and moderate neurodevelopmental disorders, and intelligence gradually increases with age. Normal babies can turn their eyes from side to side with people around 3 months old, but Down’s babies are obviously developmentally delayed. 3. Developmental delays: motor developmental delays will be clumsy and uncoordinated movements. Normal 6-month-olds can lift their heads, but Down’s babies may not be able to do so. Stature development is delayed, nutritional absorption is impaired, height and weight are lower than normal. 4. Behavioral disorders: most of them are mild, often giggle, repeat and imitate some simple actions. They are very reactive in doing things and can be destructive and aggressive. There is no effective treatment for Down’s syndrome. Pregnant women can prevent Down’s syndrome by timely prenatal screening.