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

Background: Despite the established correlation between small for gestational age (SGA) and heightened necrotizing enterocolitis (NEC) risk, the relationship between intrauterine growth, including SGA, and the occurrence of NEC remains ambiguous.

Methods: This study utilized data of very preterm infants (VPIs) with a gestational age <32 weeks from the Chinese Neonatal Network cohort study. Intrauterine growth status was categorized through birthweight (BW) percentile delineated by the Fenton growth chart.

Results: The cohort comprised 23,702 VPIs containing 1186 cases of NEC. A non-linear relationship between BW percentiles and death or NEC was identified. Infants with a BW percentile ≤23rd showed an increased risk of death or NEC. The multivariate analysis indicated a significantly higher risk of death or NEC in infants categorized between the 10th and 23rd percentiles (adjusted odds ratio [aOR] = 1.41; 95% confidence interval [CI], 1.22-1.63) and those below 10th percentile (aOR = 2.09; 95% CI, 1.74-2.52), comparing with infants in the above 23rd percentile group. Subgroup analyses yielded analogous results.

Conclusions: Intrauterine growth restriction significantly increases the risk of mortality or NEC among VPIs. The increased risk also extends to infants, particularly those within the 10th to 23rd percentile range, emphasizing the need for heightened surveillance and care.

Impact: This study explores the relationship between intrauterine growth and the occurrence of necrotizing enterocolitis (NEC). In this multicenter cohort study that included 23,702 very preterm infants (VPIs), a non-linear relationship between birth weight percentiles and death or NEC was identified. Infants with a birth weight percentile at or below 23rd showed an increased risk of death or NEC. Intrauterine growth restriction significantly increases mortality or NEC risk among VPIs with birth weight at or below the 23rd percentile. This risk extends to infants, particularly within the 10th to 23rd percentile range, highlighting the need for heightened surveillance and care.