To explore the clinical characteristics of small for gestational age (SGA) infants and appropriate for gestational age (AGA) infants among late preterm infants, and to provide a clinical basis for improving the management quality of premature infants during the perinatal period.

From November 2014 to November 2015, a total of 688 late preterm infants who were discharged from Department of Neonatology, West China Second University Hospital, Sichuan University, were chosen as study subjects. According to gestational age and birth weight, 151 SGA preterm infants were included in SGA group, 537 AGA preterm infants were included in AGA group. The clinical medical records of preterm infants were analyzed retrospectively. The general clinical data, common complications and maternal pregnancy complications between two groups of preterm infants were compared statistically.

①The birth weight of SGA group was lower than that of AGA group, and the duration of hospital stay was longer than that of AGA group, and the differences were statistically significant(P<0.05). There were also significant differences between two groups of preterm infants in constituent ratio of gender and delivery modes (cesarean section or eutocia) (P<0.05). ②The incidence rate of respiratory distress syndrome (RDS) of SGA group was lower than that of AGA group, while the incidence rates of alimentary tract hemorrhage, necrotizing enterocolitis (NEC) and hypoglycemia were higher than those of AGA group, and the differences were were statistically significant (P<0.05). ③The incidence rates of hypertensive disorder complicating pregnancy, multiple pregnancy and eclampsia of SGA group of maternal were higher than those of AGA group, while the incidence rate of premature rupture of fetal membranes was lower than that of AGA group, and the differences were statistically significant (P<0.05). ④For caesarean section delivery, there were no significant differences between mothers using and without using glucocorticoids before childbirth in the incidence rates of RDS for both SGA and AGA preterm infants.

There were more perinatal complications and longer length of stays of SGA preterm infants than AGA preterm infants. Therefore, the management and follow-up of SGA among late preterm infants should be strengthened to improve their quality of life.