Risk Factors for Necrotizing Enterocolitis in Premature Infants

Sir.—We read with interest the article on perinatal risk factors and necrotizing enterocolitis (NEC) in premature infants by Kanto et al.¹ Several recent case-control studies in the low-birth-weight (LBW) newborns^2,3 have failed to identify the risk factors for NEC, which were interpreted as significant in the earlier descriptive clinical review.⁴ In the neonatal intensive care unit, we compared perinatal histories of 23 LBW infants with NEC (mean [±SD] birth weight, 1731 ± 45.4 g) with those of 155 LBW infants of equivalent weight without NEC (mean [± SD] weight, 1693 ± 21.4 g). The two groups had equivalent mean gestational ages (33.9 weeks and 33.4 weeks, respectively). The incidences of maternal toxemia, placenta previa, intrauterine growth retardation, asphyxia, shock, apnea, hypothermia, patent ductus arteriosus, and exchange transfusion were similar in the two groups. The only adverse factor present more frequently in infants who developed NEC