Molecular detection of bacteria, placental inflammation, and neonatal sepsis risk

Objective: To identify bacteria in umbilical cord tissue and investigate the association with placental inflammation and neonatal sepsis risk score. Study design: Retrospective cohort study from 2017–2019. RNA was extracted from umbilical cord tissue and NanoString nCounter used to identify seven bacteria genera. Sepsis risk score was calculated using the Kaiser sepsis calculator. Placental histopathology was abstracted from medical records. Results: Detection of bacterial RNA in the umbilical cord (n = 96/287) was associated with high-stage maternal and fetal acute placental inflammation (maternal 35.4% vs 22.5%, p = 0.03 and fetal 34.4% vs 19.4%, p < 0.01) and maternal vascular malperfusion (36.5% vs 23.0%, p = 0.02). Detection of Ureaplasma spp. was also associated with increased sepsis risk score (1.5/1000 [0.6, 8.6] vs 0.9/1000 [0.2, 2.9], p = 0.04). Conclusion: Umbilical cord bacterial pathogens are linked to fetal and maternal placental inflammation and maternal vascular malperfusion during gestation and associated with increased sepsis risk score in the neonate.