Risk factors for necrotizing enterocolitis in small-for-gestational-age infants: a matched case-control study

Few studies have focused on the risk factors for necrotizing enterocolitis (NEC) in small for gestational age (SGA) infants. The aim of this study was to identify the risk factors for NEC in SGA newborns. This study included consecutive SGA neonates admitted to a tertiary hospital in Jiangxi Province, China from Jan 2008 to Dec 2022. Patients with NEC (Bell's stage ≥ II) were assigned to the NEC group. Gestational age- and birth weight-matched non-NEC infants born during the same period at the same hospital were assigned to the control group. The risk factors associated with NEC were analyzed with univariate and logistic regression models. During the study period, 2,912 SGA infants were enrolled, 150 (5.15%) of whom developed NEC. In total, 143 patients and 143 controls were included in the NEC and control groups, respectively. Logistic regression analysis revealed that sepsis (OR 2.399, 95% CI 1.271-4.527, P = 0.007) and anemia (OR 2.214, 95% CI 1.166-4.204, P = 0.015) might increase the incidence of NEC in SGA infants and that prophylactic administration of probiotics (OR 0.492, 95% CI 0.303-0.799, P = 0.004) was a protective factor against NEC. Therefore, sepsis, anemia and a lack of probiotic use are independent risk factors for NEC in SGA infants.