After discharge, preterm/low birth weight infants face many growth disorders such as cerebral palsy, mental retardation, visual/auditory impairment, growth retardation (especially short stature), chronic lung disease, minor neurological disorders (language disorders, learning difficulties, hyperactivity, attention deficit, behavioral disorders) and repeated re-hospitalizations, which cost parents a lot of energy and material resources and increase the mental and psychological stress. -Psychological stress. According to statistics, about 70% of the surviving preterm infants show extra-uterine growth retardation (weight, height or head circumference below the 10th percentile for the same gestational age), i.e., varying degrees of malnutrition. The younger the gestational age and the lower the birth weight, the higher the incidence of ectopic growth retardation (EUGR). This suboptimal growth status will affect long term health and increase the risk of chronic diseases in adulthood.