Neonatal Sepsis, Early-Onset

This is a prospective, single-center Phase II observational study investigating the predictive value of the "Peripheral(-muscle) Oxygenation and Perfusion Score" (POP-Score), a novel non-invasive composite index, for early detection of infection/inflammation in neonates. The POP-Score combines peripheral muscle oxygenation measured via near-infrared spectroscopy (NIRS) with routinely monitored clinical parameters (heart rate, oxygen saturation, systolic blood pressure, and subcutaneous fat thickness). The study aims to determine the optimal cut-off value of the POP-Score measured within the first 6 hours after birth to predict elevated C-reactive protein (CRP ≥20 mg/L) within 48 hours. Additionally, multi-site NIRS measurements (cerebral, peripheral muscle, intestinal, and flank) will be evaluated to assess their association with inflammation. The study includes term and moderate-to-late preterm neonates (birth weight ≥2000g) with respiratory distress, admitted to the neonatal intensive care unit at the Medical University of Graz.

Background: Necrotizing enterocolitis (NEC) and sepsis in preterm infants have been linked to intestinal immaturity and preclinical gut microbiota alterations. An important yet understudied contributor in the development of the gastrointestinal tract (GIT) is amniotic fluid (AF). Knowledge is lacking on the critical shifts that may occur in AF in extremely preterm birth. The aim of the current study is to assess the composition of AF using advanced biomedical techniques. Secondary objectives are to assess AF profiles of infants with chorioamnionitis (CAM) and/or fetal growth restriction (FGR), assess key metabolites across gestation, correlate AF profiles with neonatal outcomes, and explore associations with early gut microbiota. Methods: ln this multicenter, prospective, cohort study, AF (\~5 mL) will be collected from obstetric patients delivering their infants extremely preterm (gestational age (GA) 24+0/7-27+6/7 weeks, n=125), either during vaginal delivery or cesarean section (CS). Additionally, AF samples will be collected from a reference group (n=150), including early midtrimester (GA \<23+/7 weeks), very early and moderate to late preterm (GA 28+0/6-36+6/7 weeks), and full-term pregnancies (GA 37+0/7-41+6/7 weeks). Thorough characterization of AF will be conducted, including microbial profiling and metabolomics. Microbiota profiling of neonatal fecal samples will be conducted to assess the association between AF and early neonatal gut colonization patterns. Discussion and expected results: AF profiles associated with CAM and/or FGR in extremely preterm infants are expected to be identified, as well as relevant associations with neonatal health outcomes (including NEC and sepsis) and early neonatal gut colonization patterns. The current study will not only increase the understanding of the GIT development and the pathogenesis of NEC and sepsis but may also aid in the identification of high-risk infants. In the future, these findings may facilitate early targeted microbiota-based interventions to prevent disease progression and ultimately improve clinical outcomes.