[Effect of postnatal enteral feeding patterns on infant catch-up growth in hospitalized small-for-gestational-age...

Objective: To describe physical growth trajectories during infancy among hospitalized small-for-gestational-age (SGA) infants and to examine the association between predominant feeding patterns during early postnatal life and catch-up growth in infancy. Methods: This prospective cohort study included SGA infants who were born and hospitalized at Peking University Third Hospital between January 1 and December 31, 2024, and who completed regular follow-up. Perinatal characteristics, predominant feeding patterns during the first 6 months after birth, and anthropometric measurements from birth to 12 months of age were collected. Growth was evaluated using weight-for-age Z score (WAZ), length-for-age Z score (LAZ), and head circumference-for-age Z score (HCZ). Overall catch-up growth was defined as an increase of >0.67 in at least one anthropometric Z score at 10-12 months compared with birth. Multivariable logistic regression was used to assess the association between early feeding patterns and catch-up growth after adjustment for potential confounding factors. Results: A total of 126 SGA infants were included, comprising 67 males (53.2%) and 59 females (46.8%). Gestational age ranged from 26.3 to 40.5 weeks, with a median of 35.4 weeks and a mean of 34.53 weeks. Birth weight ranged from 450 to 3 000 g, with a median of 1 880 g and a mean of 1 865.3 g. Anthropometric Z scores initially declined after birth and subsequently increased. Head circumference showed the fastest catch-up growth, followed by weight, whereas catch-up growth in length was relatively slower. Among the 119 infants (94.4%) with complete follow-up data, catch-up growth in weight, length, and head circumference was achieved by 74 (62.2%), 32 (26.9%), and 60 (50.4%) infants, respectively; 86 infants (72.3%) achieved overall catch-up growth. The proportions of infants achieving catch-up growth in weight, length, and head circumference did not differ significantly among feeding pattern groups (χ²=1.535, 0.587, and 0.416, all P>0.05). After adjustment for preterm birth, birth weight, sex, SGA subtype, and fetal growth restriction, predominant feeding pattern during the first 6 months was not independently associated with catch-up growth in weight, length, or head circumference at 10-12 months (all P>0.05). Conclusions: Catch-up growth during the first year of life was heterogeneous among SGA infants, with different recovery rates across anthropometric indicators. No independent association was observed between predominant feeding pattern during early postnatal life and catch-up growth at 10-12 months.