A Multicenter Study On The Influencing Factors Of Extrauterine Growth Retardation In Very Low Birth Weight Infants And Follow-up Of Prognosis

Objective:Based on a prospective birth cohort study,we analyzed the baseline incidence of necrotizing enterocolitis(NEC)in very low birth weight infants in a region represented by the participants of the sino-northern neonatal network(SNN),and investigated the risk factors affecting the onset,progression and death of NEC.The study will provide a clinical basis for early identification of high-risk infants,optimal clinical management,and prevention of NEC and its further development.Methods:1.The very low birth weight infants(VLBWI)with birth weight <1500g admitted to the participating units of the SNN from January 1,2019 to December 31,2021 were prospectively collected as the study subjects.2.The study subjects were divided into NEC and non-NEC groups according to the diagnosis of Bell staging,and the current status of the occurrence of NEC was analyzed.Infants diagnosed with NEC ≥ stage II during the observation period were included in the case group,and three non-NEC infants were matched to form a control,and clinical data were collected to analyze the risk factors affecting the occurrence of NEC by statistical methods.3.Infants with NEC ≥ stage II were included as the study population to describe NEC deaths stratified by weight and gestational age,and antibiotic indicators such as antibiotic spectrum index(ASI)were introduced to analyze the risk of progression to surgical NEC and short-term death factor.Results:1.population included and current status of NEC occurrence: 4365 cases of VLBWI were included from January 1,2019 to December 31,2021,of which 2251(51.57%)were males and 2114(48.43%)were females.The average birth weight was1180.29±224.13 g and the average gestational age was 29.60±2.17 weeks.268(6.14%)infants with NEC were included,of which 136(3.12%)were in stage I and 132(3.02%)were in stage II+III.With the increase of gestational age and birth weight,the incidence of NEC decreased accordingly(P=0.001).2.Risk factors affecting the onset of NEC: Multi-factorial logistic analysis showed that the combination of antibiotics(P=0.001,OR=1.976)and hypotension(P=0.004,OR=2.224)were independent risk factors for the onset of NEC.3.Treatment and death of NEC: Among 132 VLBWI with NEC ≥ stage II: 62(46.97%)with stage II and 10(16.13%)deaths,including 14(22.58%)surgical treatment(surgical treatment + abdominal drainage)and 7(50.00%)surgical deaths;70(53.03%)with stage III and 32 cases(45.72%),of which 48 cases(68.57%)were treated surgically and 23 cases(47.92%)died surgically.There were 42(31.82%)deaths in the included population,of which 62(46.97%)were surgically treated and 30(48.39%)were surgical deaths.There were 44 cases(48.88%)of surviving infants with extrauterine growth retardation at discharge.In 32 surviving infants after surgery,4 cases(12.50%)were complicated with short bowel syndrome.The overall age at onset was 19.30±12.17 days,with a peak incidence at postmenstrual age 30-33 weeks,accounting for 64.39% of the total number of cases.4.The condition requiring surgical intervention(P=0.009,OR=3.191)was an independent risk factor for death in children with NEC;early postnatal formula feeding(P=0.005,OR=5.231)and high ASI(P=0.003,OR=1.013)were independent risk factors for progression of NEC to surgical treatment.Conclusion:1.Multicenter results showed that the incidence of NEC in very low birth weight infants was 6.14% and 3.02% in stage II and above.The incidence of NEC gradually decreased with increasing gestational age and birth weight.Standardized management of infants with peak incidence at 30-33 weeks of postnatal days,correction of early postnatal hypotension,maintenance of intestinal blood supply,avoidance of severe anemia,and enhanced antibiotic management are expected to reduce the risk of NEC in VLBWI.2.31.82% of VLBW infants with NEC ≥ stage II had a mortality rate,including46.97% with surgical intervention and 48.39% with surgical mortality.Conditions requiring surgical intervention are a high risk factor for death in children with NEC,while promoting early postnatal breastfeeding and avoiding prolonged exposure to broad-spectrum antibiotics may reduce the risk of surgical NEC.Surviving infants also face a higher incidence of complications and comorbidities that affect the quality of long-term survival.