Calculator and Prediction Score for Early-onset Neonatal Sepsis in Asymptomatic Term Infant: A Determinant Model

Background: Risk estimation of early-onset neonatal sepsis (EONS) in asymptomatic term infants is sometimes considered less often among clinician. The cumulative case number is large and we aimed to develop a calculator and scoring system as a determinant model of early onset neonatal sepsis (EONS) in asymptomatic term infants with premature rupture of the membranes (PROM) by combining maternal factors and umbilical cord blood examination to guide more targeted antimicrobial therapy. Method This is a cross-sectional study involving infants born to mothers with premature rupture of the membranes for > 12 hours who are term and asymptomatic. We investigated the maternal clinical status, maternal blood and urine examination and infant cord blood examination. Independent predictors were identified by using bivariate and multivariable analysis, then developed into a calculator and scoring system with ideal and optimal cut-off. Result A total of 334 infants with PROM were involved in this study with 62 diagnosed with EONS. The overall incidence in all term births of culture-proven EONS was 4.6 per 1,000 live births. Independent predictors were vaginal birth (OR 2.39; 95%CI 1.19, 4.80), foul-smelling amniotic fluid (OR 1.93; 95%CI 1.01 -3.70), maternal blood WBC > 15,000/mm3 (OR 2.01; 95%CI 1.09-3.73), cord blood WBC > 15,000/mm3 (OR 1.84; 95%CI 1.01-3.39), cord blood C-reactive protein (CRP) > 0.15 mg/L (OR 1.16; 95%CI 1.01-1.33), and cord blood interleukin-6 (IL-6) > 10 ng/L (OR 5.38; 95%CI 2.88-10.04). We developed two models: IndEONS 1 (with IL-6) and IndEONS 2 (without IL-6), both in the form of a calculator and scoring system. All models have good performance with consistent validity. The result was infant stratification into low, medium, or high EONS risk each with a corresponding management recommendation. Only high risk infants should get empirical antibiotics. Conclusion A new calculator and scoring system are a useful tool to quantify EONS risk among asymptomatic term infants.