Objective To investigate the effect of post-discharge formula(PDF)to preterm and low-birth-weight infants. Methods A total of 59 preterm and low-birth-weight infants discharged from The NICU of the Second Hospital of Tianjin Medical University were chosen for this study.According to feeding pattern,they were assigned to two groups:breast milk(BM)+PFT-fed(group Ⅰ,n=29),PDF-fed(group Ⅱ,n=30).Their body weight,length and head circumference and so on were measured for 6months after hospital.These indices were c...