Necrotizing Enterocolitis in Full-Term Infants: Case–Control Study and Review of the Literature

OBJECTIVE: To examine the increasing number of full-term infants at our hospital exhibiting necrotizing enterocolitis (NEC) in order to characterize these cases and to discover common risk factors. METHODS: Medical charts were reviewed for all full-term infants (gestational age > 36 weeks) that were born in our institution during a 5-year period (from January 1, 1998 to December 31, 2002) and that developed definite NEC. Data regarding the rate of Cesarean section (CS) in our institution over the study period and five years prior to the study was also recorded. RESULTS: During the 5 years of the study, 14 full-term infants were found to have NEC. The incidence of NEC in full-term infants increased from 0.16 to 0.71 per 1000 live births in the 5-year period. Mean birth weight was 2829 g. All the NEC infants except one were delivered by CS, and all of them were fed either with a mixture of breast milk and formula or entirely by formula. Seven of the infants (50%) had no major known risk factors predisposing them for NEC. Mean age of disease onset was very early (4.1 days) in most of the infants (12 infants), and the colon was the main NEC site. The short-term outcome was favorable in all but one case, which required explorative laparotomy for intestinal perforation. The number of infants born by CS has been steadily increasing, and was almost three times greater during the study period in comparison to the preceding years. CONCLUSIONS: The etiology of NEC in the full-term population seems to differ from the etiology for the preterm group in its intestinal location and in the timing of its onset. The increase in the rate of CS over the years might be related to the concurrent increase in NEC, and this relationship should be further investigated.