Necrotizing Enterocolitis: Incidence, Risk Factors, and Associated Morbidities in a Large Cohort of Infants with Very Low Birth Weight

Abstract

Objective: Necrotizing Enterocolitis (NEC) causes morbidity and mortality in infancy. This study investigated the incidence, risk factors, morbidity, and mortality rates in a cohort of infants with very low birth weight in Brazil. Study Design: Data were collected from 17 Neonatal Intensive Care Units (NICUs) for infants with very low birth weight of gestational ages 24-36 weeks and delivered during 2015-2019. Data were analyzed using a multivariate logistic regression analysis. Results: Of 7793 newborns, 561 (7.2%) met the criteria for NEC, of whom 295 (52%) underwent clinical treatment and 266 (48%) underwent surgical intervention. NEC incidence varied across neonatal units (from 4.5% to 12.9%) and was stable during the study period for the whole population. However, the incidence over the study period increased from 9.7% in 2015 to 13.9% in 2019 for infants weighing<1000 g. Patients with NEC had lower birth weight, gestational age, and Apgar scores and significantly higher mortality rates than those without (p<0.001). Late-onset sepsis, birth weight, and mechanical ventilation were independent risk factors for NEC. Conclusion: NEC is strongly associated with NICU mortality and largely varies between infants in the NICU. Moreover, the incidence of NEC among extremely low birth infants is constantly increasing.