Preterm infants are often significantly growth retarded at the time of hospital discharge.They often in the nutritional crisis after hospital discharge,and should be carefully follow up evaluated.Preterm formula and fortified breast milk may improve the growth of preterm infants and is a reasonable option for preterm infants.Preterm formula and fortified breast milk are recommended for preterm infants with weights below the 10th percentile for age at the time of hospital discharge and those birth weights below 1 500 g.After hospital discharge,exclusively human milk-fed preterm infants are at increased risk for suboptimal growth compared to formula-fed infants.Infants with BPD are at increased risk of growth retardation after hospital discharge.Protein and mineral enriched formula may provide short-term growth catch-up.