The standard height for a 3.5 year old boy is 100.6cm and for a 3.5 year old girl is 99.4cm. Boys and girls are considered approximately normal if they are within one standard deviation of the next, which means that boys are considered normal between 98-103.2cm and girls are normal between 96.8-102cm. If a girl’s height is below 92.4cm and a boy’s height is below 93.4cm, it is considered dwarfism. From the age of 3 weeks, if the child is short, you need to take the child to the hospital for a bone age test, which is an orthopantomogram of the left wrist, which can truly reflect whether the child’s actual height is normal and whether the child is a late grower or truly short. If it is not a late growth, but the height with the child’s bone age are short, it needs intervention treatment, further guidance and intervention according to the actual situation of the child.