Abstract: Objective To investigate the incidence and influencing factors of extrauterine growth restriction (EUGR) among late preterm infants classified as appropriate for gestational age (AGA). Methods A total of 236 late preterm AGA infants admitted to Hefei Maternal and Child Health Hospital and the Second Affiliated Hospital of Anhui Medical University from June 2022 to June 2024 were enrolled using a random number table selection method. Descriptive analysis was performed to assess the incidence of EUGR. Univariate and multivariate logistic regression analyses were conducted to examine the associations between baseline characteristics and the occurrence of EUGR. Results Of the 236 neonates evaluated, 58 cases exhibited EUGR, yielding an incidence rate of 24.58%. Compared with the non-EUGR group, the EUGR group demonstrated a significantly higher prevalence of gestational complications, male sex, very low birth weight (VLBW), low birth weight (LBW), neonatal complications, and feeding intolerance, as well as a prolonged time to achieve full enteral feeding (all P<0.01). Multivariate logistic regression analysis revealed that gestational complications (OR=5.005, P<0.05), male sex (OR=5.427, P<0.05), VLBW at birth (OR=185.089, P<0.05), LBW at birth (OR=4.120, P<0.05), duration to full enteral feeding (OR=1.315, P<0.05), neonatal complications (OR=2.598, P<0.05), and feeding intolerance (OR=4.805, P<0.05) were independent risk factors for EUGR. Conclusions This study demonstrates a relatively high incidence of EUGR among late preterm AGA infants. Factors including gestational complications, sex, birth weight, time to achieve full enteral feeding, neonatal complications, and feeding intolerance are closely associated with the development of EUGR. These findings underscore the necessity for enhanced monitoring and targeted interventions for high-risk populations in order to optimize extrauterine growth and developmental outcomes in this vulnerable cohort.

Key words: Late preterm infants, Appropriate for gestational age (AGA), Extrauterine growth restriction (EUGR), Gestational complications, Feeding intolerance, Neonatal complications