Necrotizing enterocolitis (NEC) is the most common life-threatening gastrointestinal emergency in prematurity. The pathophysiology is multifactorial and remains incompletely understood. Early diagnosis and treatment could reduce the risk of mortality and morbidity. We aimed to identify factors associated with NEC in preterm newborns.

This case–control study included all preterm newborns presenting with NEC and managed between January 1, 2009 and December 31, 2018 in the neonatal intensive care unit of Nancy. For each case, two controls were matched according to three criteria: gestational age (WG), date of birth, and mode of delivery. Antenatal, peripartum, and postnatal risk factors prior to NEC were analyzed.

A total of 292 infants were involved in the study, 113 of whom had NEC. Mean gestational age for newborns with NEC was 29 WG, and mean birth weight, 1340 g. Only early-onset infection was identified as a significant risk factor for NEC (15% vs. 6.6% for infection p<0.04, and 28.3% vs. 16.4% p<0.02 for infection and sepsis, NEC vs. controls, respectively). Late-onset feeding and initial continuous enteral feeding were significantly associated with the occurrence of more severe NEC (p<0.02 and p = 0.03, respectively).

The results of this study are consistent with intestinal dysbiosis being a risk factor for NEC. Early-onset infection was found to be a significant risk factor. Enteral feeding practice may also be associated with NEC.