Does the duration of empiric antibiotic treatment influence NEC incidence and severity relative to placental pathology?

Necrotizing enterocolitis (NEC) remains a leading cause of mortality in preterm infants. Studies show that exposure to chorioamnionitis is associated with increased rate of NEC. The influence of the early antibiotic exposure provides contrasting findings, with a few studies demonstrating an increased risk of NEC with prenatal and postnatal antibiotic treatment, and others showing a decreased NEC risk. Far fewer reports delineate the impact of the duration of early antibiotics or the potential confounding of antibiotics by placental pathology on incidence of NEC. The provision of antibiotics following birth is associated with increased risk of NEC secondary to changes in the gut microbiome, intestinal epithelium maturation, and the intestinal barrier function. This report presents current evidence about the clinical impact of intrauterine environment and postnatal antibiotic exposure on the intestinal injury in preterm infants. We present information from our own research in conjunction with information collected from an extensive search in the databases PubMed, EMBASE, and Scopus. Both translational and prospective clinical studies are needed to fully understand the combined impact of placental pathology and postnatal antibiotic exposure on the neonatal morbidities and mortality.