Risk Factors For Necrotizing Enterocolitis In Neonates: Retrospective Case-Control Study

Aims:Necrotizing enterocolitis(NEC) in neonates is one of the common and devastating diseases in neonates, especially for the premature. Various studies have been undertaken to investigate the risk factors for NEC. Commonly observed risk factors appear to be prematurity, low birth weight, enteral feeding, blood transfusion, and sepsis. Breast milk and probiotics have been demonstrated to be protective factors. Recently, intrahepatic cholestasis of pregnancy(ICP), family history of allergic diseases, meconium aspiration syndrome(MAS) and congenital heart disease(CHD) have been reported to may be also associated with an increased risk of NEC. We aimed to evaluate risk factors for NEC in different gestational age(GA) groups.Methods:Risk factors associated with NEC were investigated using a retrospective case-control design. Patients with Bell’s stage NEC ≥II were divided into three groups based on GA: I, <34 weeks; II, ≥34 weeks but <37 weeks: III, ≥37 weeks. Each case was paired with two GA- and weight-matched controls. Descriptive assessment of patients was conducted to examine the variables of interest. Data are the mean ± standard deviation for continuous variables, and absolute frequencies or percentages for categorical variables. The chi-square test was used for categorical variables. For continuous variables, groups were evaluated using the t-test. Conditional logistic regression analyses were carried out to determine the possible risk factors for NEC after inclusion in the model of significant variables identified in univariate analyses.Results:A total of 238 cases and 476 controls were enrolled. Variation in the months when NEC was diagnosed was noted, with a peak in January and a trough in August. Intrahepatic cholestasis of pregnancy(ICP) and transfusion with packed red blood cells were significantly associated with NEC in preterm infants. Meconium aspiration syndrome(MAS) was an independent risk factor for a greater chance of NEC development in full-term infants. Postnatal asphyxia and sepsis were associated with an increased risk of NEC in all groups. Probiotics use were associated with a reduced risk of NEC. Patients aged >34 weeks with congenital heart disease were more likely than controls to have NEC.Conclusions:A range of conditions,such as ICP、MAS、CHD、transfusion with packed red blood cells、postnatal asphyxia 、sepsis were found to be associated with an increased risk of NEC. Probiotics use were associated with a reduced risk of NEC. In this study, ICP and MAS may be new risk factors for NEC.