525 - Association between intrauterine growth and the risk of necrotizing enterocolitis: a multicenter cohort study

Poster Number: 525
Publication Number: 525.1954

Background: The association between intrauterine growth status and the risk of necrotizing enterocolitis (NEC) is still not fully understood. Small for gestational age (SGA) infants are known to have an increased risk of NEC, but the relationship between appropriate for gestational age (AGA) with variable intrauterine growth status and NEC is not clear.

Objective: This study aims to examine the association between variable intrauterine growth status and the risk of NEC in infants.

Design/Methods: Chinese Neonatal Network (CHNN) consisting of very preterm infants enrolled between 2019 and 2021 was utilized. Intrauterine growth status was assessed using birthweight percentile determined by the Fenton curve. The relationship between birthweight percentile and the incidence of death or NEC was analyzed using a generalized additive model. A two-piecewise linear regression model was employed to perform threshold effect analysis. Finally, a multivariate analysis was conducted to determine the association between intrauterine growth and the risk of death or NEC.

Results: The study included a total of 26,748 very preterm infants, out of which 1,342 cases of NEC were observed. A non-linear relationship between birthweight percentile and death or NEC was identified. Infants with a birthweight percentile of 23rd or lower had an increased risk of death or NEC. In addition, the population was divided into three groups based on birthweight percentile: less than 10th percentile, 10th-23rd percentile, and above 23rd percentile. Multivariate analysis indicated a significantly higher risk of death or NEC in both the 10th-23rd percentile group (adjusted odds ratio [OR], 1.72; 95% confidence interval [CI], 1.48-2.00) and the less than 10th percentile group (adjusted OR, 2.57; 95% CI, 2.17-3.04) compared to the above 23rd percentile group. Subgroup analysis based on maternal hypertension status, infant sex, and type of birth yielded similar results.

Conclusion(s): Intrauterine growth restriction poses a heightened threat of mortality or NEC among extremely premature infants. This risk is not limited to SGA infants alone, but also extends to those who fall within the lower percentiles of AGA infants, specifically the 10th to 23rd percentiles. Consequently, it is imperative that these infants receive an increased level of vigilance and care.