Utility of hematologic and volume, conductivity, and scatter parameters from umbilical cord blood in predicting chorioamnionitis.

We evaluated the utility of routine hematologic parameters and volume, conductivity, and scatter (VCS) parameters from umbilical cord blood in predicting pathologically confirmed chorioamnionitis. Chorioamnionitis is strongly associated with early neonatal sepsis and is the major in utero source of infectious exposure. We prospectively identified mothers who had placenta submitted for pathology and subsequently identified corresponding neonate cord blood sent for routine blood typing (n = 99). Cord blood was then sent for routine complete blood count with differential (CBCD). Among the same neonates, we retrospectively identified those who had peripheral blood sent for CBCD. We collected VCS parameter data, which are used in determining an automated leukocyte differential, from our hematology analyzer. Routine hematologic as well as VCS parameters from both cord and peripheral blood were then evaluated for predicting pathologically confirmed chorioamnionitis. In the study population, the absolute neutrophil count, neutrophil differential, mean neutrophil conductivity, and neutrophil conductivity standard deviation (SD) from cord blood showed the best predictive ability for chorioamnionitis. Among neonates with intrapartum antibiotic prophylaxis exposure, the band differential, immature neutrophil precursor differential, and neutrophil conductivity SD showed the best predictive ability. Lastly, among the neonates who had peripheral blood CBCD, the band differential and immature neutrophil precursor differential showed the best predictive ability. Overall, the peripheral blood band differential and immature neutrophil precursor differential showed better specificity and positive predictive value for chorioamnionitis than the cord blood parameters. However, the cord blood absolute neutrophil count, neutrophil differential, and mean neutrophil conductivity showed better negative predictive value. Cord blood can be a valuable source of diagnostic laboratory testing for neonates because of their small blood volume. This is the first study demonstrating that routine hematologic and VCS parameters from cord blood can be used to predict pathologically confirmed chorioamnionitis.