Relationship between the neonatal white blood cell count and histologic chorioamnionitis in preterm newborns

Objective: The aim was to examine the relationship between neonatal white blood cell (WBC) count and the diagnosis of histologic chorioamnionitis (HCA). Design: We measured WBC, a widely used marker of inflammation, to evaluate whether the values at birth were associated with HCA. Setting: NICU, Department of Pediatrics of Padua University, Padua, Italy. Subjects: WBC count was evaluated in 71 preterm neonates (<32 weeks of gestation) with HCA and in a control group without HCA on day 1, 3, and 6 after delivery. Logistic regression analysis and diagnostic accuracy analysis were used to assess the association between WBC counts and HCA. Main results: WBC levels were significantly higher in infants with HCA than in those without HCA (Median IQR, WBC (x10 ⁹/l): day 1, 13.2 (6.2-21.8) vs 8.1 (6-11.4), p < 0.001; day 3, 17.4 (11.4-26.9) vs 6.3 (5.2-8.3), p < 0.001; day 6, 18.4 (11.1-31) vs 6.5 (4.4-9), p < 0.0001). The neonatal WBC count on the third day of life was the most sensitive parameter associated with HCA (sensitivity: 0.80; specificity: 0.88). The cut-off value based on the ROC curve was 10 (x10⁹/l). Conclusions: WBC count in the third day of life is strongly associated with HCA.