Smaller than gestational age (SGA), also known as intrauterine growth retardation, is a condition in which the birth weight of a newborn is less than the 10th percentile or 2 standard deviations from the average weight for the same gestational age. SGA is one of the causes of short stature, mental retardation, sexual retardation and other diseases in children as adults. There are many causes of SGA, including maternal factors, fetal factors, placental and umbilical cord factors, and endocrine factors. The incidence of SGA in the population is about 7.5% in China, of which 10%-15% of children with SGA do not have postnatal catch-up growth. About half of these children with growth disorders will be 2 standard deviations below the average height of the normal population in adulthood, i.e. short stature. Therefore, SGA children should have good health care from infancy and have regular physical examinations so that they can know the height and weight of their height and also know the annual height gain value to see if their height is normal. The use of growth hormone for the treatment of children younger than fetal age with dwarfism has been around for many years, and since 1960, foreign scholars have been discussing the use of growth hormone for the treatment of SGA and have conducted a lot of clinical research since then. The FDA and the LWPES guidelines recommend that treatment should be started as soon as possible after the age of 2 years without catching up, the earlier the better. In March 2003, the European Medicines Evaluation Agency (EMEA) also officially approved the use of recombinant human growth hormone for the treatment of children with SGA dwarfism who fail to achieve catch-up growth at the age of 2 years. When it comes to treating dwarfism with growth hormone, the first reaction of many parents is that growth hormone is a “hormone” and children will have adverse reactions if they use it. In fact, what people usually call “hormone” often refers to glucocorticoids, but there are many other hormones in the human body, such as thyroid hormone, which is essential for human growth and intellectual development, and growth hormone, which is necessary for linear bone growth. Growth hormone is a protein hormone secreted by the anterior pituitary gland and is composed of 191 amino acids. It is essential for the regulation of normal human growth from birth to adulthood, and is the only hormone that causes linear skeletal growth. Growth hormone used as a drug is synthesized using recombinant genetic technology and is identical to the growth hormone produced by the human pituitary gland. Glucocorticoid, on the other hand, is a steroid hormone secreted by the adrenal cortex. Properly injected growth hormone and timely review and follow-up will not produce glucocorticoid-like effects or side effects.