Necrotizing Enterocolitis in Small-for-Gestational-Age Neonates: A Matched Case-Control Study

Abstract

Background: Small for gestational age (SGA) neonates are at increased risk of mortality and morbidity, including necrotizing enterocolitis (NEC), but detailed information on the incidence and risk factors of NEC in SGA neonates is lacking. Objective: This study aims to estimate the incidence of NEC in a large cohort of SGA neonates, compared to appropriate for gestational age (AGA) neonates. Methods: We included all SGA neonates without congenital malformations admitted to our neonatal nursery between 2004 and 2013. Neonates in the SGA group were matched for gestational age with a control group of AGA neonates admitted during the same study period. We recorded the occurrence of NEC and studied the association with SGA and other potential risk factors. Results: A total of 475 SGA neonates were matched for gestational age at birth to 475 control AGA neonates. The incidence of NEC in the SGA group was 3.2% (15/475) versus 1.3% (6/475) in the AGA group (OR 2.55, 95% CI 0.98-6.63, p = 0.047). The incidence of NEC in the subgroups with mild, moderate and severe SGA was 2.3% (5/215), 4.7% (5/1.07) and 3.2% (5/153), respectively (p = 0.531). Conclusions: The risk of development of NEC is more than twofold increased in SGA neonates compared to AGA neonates. We found no association between the severity of SGA and NEC.