Comparison of hematologic indices and markers of infection in umbilical cord and neonatal blood

Objective: Evaluation of a neonate for suspected early neonatal sepsis routinely includes blood tests such as complete blood count, C-reactive protein (CRP) and culture. In order to obviate the need for venepuncture, we prospectively compared these tests in paired samples from umbilical cord and peripheral venous blood drawn during the first hours after birth in both preterm and term infants. Methods: Paired blood samples were studied from asymptomatic neonates with risk factors for early sepsis. Data were collected on maternal and neonatal factors that may have influenced the correlation between the tests. Results: Three hundred fifty pairs of samples were studied. Significant correlation between umbilical cord and peripheral venous samples was found for white blood cell (WBC; r=0.683) and platelets (PLT) (r=0.54). Correlation for hemoglobin was lower (r=0.36). No cases of early neonatal sepsis were detected. However, contamination rates were 12% in umbilical cord blood and 2.5% in peripheral venous blood cultures. WBC rose after birth and the 90th percentile rose from 22500 in umbilical cord blood to 29700 in peripheral blood. Conclusions: Screening for sepsis with umbilical cord CBC may be useful provided normal ranges are adjusted accordingly.