Can Fetal Umbilical Venous Blood Be a Reliable Source for Admission Complete Blood Count and Culture in NICU Patients?

Abstract

Background: Minimizing initial neonatal blood draws and their associated pain is important. The placenta has ample fetal blood that is otherwise discarded; obtaining admission laboratory evaluations from fetal umbilical venous blood (FUVB) may provide a suitable alternative. Objective: We hypothesized that obtaining an aerobic bacterial blood culture (BCX) and a complete blood count with manual differential (CBC/diff) from FUVB is feasible and yields results comparable to those obtained directly from the neonate. Study Design: BCX and CBC/diff were attempted on paired samples from FUVB (in the delivery room) and neonatal blood (shortly after NICU admission) of 110 patients. The paired t test, Pearson’s correlation coefficient (R), and multivariable linear regression were used for data analysis. Results: Positive BCXs were found in 9 of 108 FUVB samples compared to 1 of 91 neonatal samples. Three out of 9 FUVB cultures were true pathogens, including 2 Escherichia coli and 1 viridans group streptococcus, all with negative corresponding paired neonatal cultures. There was 1 positive neonatal BCX, E. coli, with a negative paired FUVB culture. Neonatal hemoglobin (Hb), platelets (PLT), and white blood cells (WBC) all significantly (p < 0.0001) correlated with the paired FUVB samples (R = 0.50, 0.49, and 0.84, respectively). Hb, PLT, and WBC values were clinically comparable but statistically higher in neonatal blood (the differences were 2.3 g/dL, 30,000 cells/μL, and 2,800 cells/μL, respectively; p < 0.007 for all comparisons). Conclusions: FUVB is suitable for obtaining CBC/diff. FUVB is an appropriate second source for BCX as it yields additional true pathogens. Our findings may support the presence of “culture-negative sepsis” in some neonates.

Feasibility and accuracy of cord blood sampling for admission laboratory investigations: A pilot trial

“…Notwithstanding these issues, our trial had a high enrolment rate (72%) when compared to similar studies. In our cohort, the rate of delayed cord clamping was much higher than previous studies (Carrol et al 8,13 . (29%) 15 (44%)).…”

“…Most importantly, our study found a significantly higher UVB BC volume inoculum when compared to the neonatal BC volume in addition to a low rate of contamination. Previous studies evaluated the use of UVB BC for early onset sepsis, showing a variable contamination rate (0–12.5%) 8,9,13,15,17 . We had one false‐positive UVB BC, which happened early in the trial.…”

“…A clinically significant difference in the haematological parameters was determined from the available literature. Previous data suggests that the platelet count is the most likely variable to differ as a result of the method of collection 14 A clinically significant difference of 40 000 μ/L 8 was determined to be clinically relevant. In order to detect a difference of 40 000 μ/L or greater with 90% power and P < 0.05 a sample size of 45 was required.…”

“…In this context, the possibility of using the placenta, whose blood volume ranges from 15 to 34 mL/kg, for sampling a larger amount of blood for initial tests seems attractive 6,7 . It has previously been shown that umbilical venous cord blood (UVB) correlates with blood tests obtained directly from the neonate 8,9 . Further, adoption of this approach is associated with a reduction in blood transfusion rates and its possible complications 10 .…”

Clinical and Immunological Metrics During Pediatric Rhesus Macaque Development

“…Information currently available about pediatric immunological development mainly derives from studies using the mouse model or human cord blood, both of which have limited translational applications (17)(18)(19). For example, clinical parameters in human cord blood, such as neutrophil and lymphocyte numbers, are rarely equivalent to neonatal and infant blood values (20)(21)(22)(23). In addition, information in the veterinary medicine literature describes the developmental immune system in companion and food-producing animals but is limited due to stark differences in physiology between these animals and humans.…”