Comparison Of Clinical Feature Of Early And Late Onset Necrotizing Enterocolitis In Full-term Infants

Objective : Necrotizing enterocolitis(NEC)is the most severe intestinal inflammatory disease during neonatal period,which have high rate of morbidity and mortality.Most of NEC infants are preterm,and most term infants occur within 7 days after birth.Little studies focus on the clinical feature of NEC in full term infants who developed NEC at more than 7 days after birth.To evaluate the risk factors of morbidity and mortality among full-term infants with early onset necrotizing enterocolitis(EO-NEC)and later onset NEC(LO-NEC).Methods:Medical data of 253 patients diagnosed as NEC from 1996 to 2015 were reviewed.Patients were divided into EO-NEC group(n=150)and LO-NEC group(n=103)according to the onset age(within or beyond 7days of life),.The baseline medical information including demographic features of perinatal period,complications and treatment protocols for infants were compared between two groups.Results:The average onset time of EO-NEC were 2 days after birth,while LO-NEC occurred 14 days.Gestational age was larger in EO-NECgroup than in LO-NEC(39.2±1.19 vs.38.82±1.11,t =2.205,P =0.029,weeks).Advanced NEC(27.3% vs.12.6%)and higher prevalence of peritonitis(20.6% vs.8.3%)were found in EO-NEC group compared with LO-NEC group(P<0.05).No significant difference was found in the rate of needing surgical intervention(82.9%vs.76.9%,P=0.94)and mortality between EO-NEC group and LO-NEC group was found(16%vs.11.7%,P=0.331).Within EO-NEC group,higher incidence of advanced NEC,peritonitis,sepsis,respiratory failure,and renal impairment,shock and multiple organ dysfunction syndrome were found in death group than in survival group(P < 0.05).Meanwhile,within LO-NEC group,higher prevalence of advanced NEC,peritonitis,respiratory failure,sepsis and shock were also found in death group than in survival group(P<0.05).The independent risk factors of poor prognosis in infants with EO-NEC were peritonitis(P=0.000,OR:17.49,95%CI:5.891-51.931)and kidney failure(P=0.003,OR:10.331,95%CI:2.7-154.173).Peritonitis(P=0.001,OR:20.579,95%CI : 3.624-116.85)and(P=0.027,OR:12.03,95%CI :1.326-109.141)might also lead to poor outcome in patients with LO-NEC.Conclusions:Infants with EO-NEC who occur at 2 days after birth had larger gestational age,distinct characteristic of severe medical conditions than LO-NEC whose onset time is at 14 days after birth.The risk factors of mortality among infant with EO-NEC were peritonitis and kidney failure after NEC.For infant with LO-NEC,peritonitis andrespiratory failure after NEC might lead to poor outcome.