Umbilical Cord Blood as an Alternative to Neonatal Blood for Complete Blood Count

The present study assessed the similarity between umbilical cord blood (UCB) and neonatal blood (NB) laboratory test results at birth.

The study included very preterm neonates (<32 weeks gestational age) who were subjected to a complete blood count measured in both UCB and NB drawn within 2 hours after birth. Median hemoglobin (Hb) and hematocrit (Hct) concentrations were compared between UCB (venous samples) and NB (venous, arterial, or capillary samples).

The study found-

• Enrollment of 432 neonates with paired UCB and NB values for the study.
• Hb concentration in UCB was 14.7 g/dL compared with 14.8 g/dL in venous NB samples, 13.9 g/dL in arterial NB, and 18.7 g/dL in capillary NB.
• A correction factor of 1.08 for converting Hb values from UCB to venous NB. 
• Median Hct concentration in UCB was 0.45 L/L compared with 0.48 L/L in venous NB, 0.42 L/L in arterial NB, and 0.57 L/L in capillary NB.

It can be concluded that Hb and Hct concentrations are similar in UCB and venous blood in very preterm infants. Thus, it represents a valid alternative for NB tests at birth.

Heeger LE, Koster MIJ, Caram-Deelder C, et al. Umbilical Cord Blood as an Alternative to Neonatal Blood for Complete Blood Count: A Comparison Study. The Journal of Pediatrics. 2024;271. DOI:https://doi.org/10.1016/j.jpeds.2024.114059