A comprehensive study of umbilical cord blood cell developmental changes and reference ranges by gestation, gender and mode of delivery.

OBJECTIVE: The purpose of this study was to determine the normal hematological values in cord blood during gestation, the impact of the type of delivery and differences in gender.

STUDY DESIGN: The database included 10 287 live births of 30-44 weeks gestation from cesarean or vaginal deliveries. Cord blood was collected into bags containing lyophilized heparin. Specimens were stored for 24 h or less and analyzed using the SysmexXE-2100. Data from cesarean births were used to evaluate developmental hematopoietic changes.

RESULT: Increases during maturation occurred in hemoglobin, hematocrit, red blood cell count, and decreases in mean corpuscular volume and mean corpuscular hemoglobin. The number of nucleated red blood cells per 100 white blood cells decreased but absolute counts remained constant. Quantitative counts of white blood cells, neutrophils, monocytes (MON), eosinophils and lymphocytes (LYMP) increased, but percentages of lymphocytes and monocytes decreased. Platelets increased from 30-35 weeks.

CONCLUSION: Reference ranges were established for cord blood. Erythroid and myeloid cells show developmental changes. Mode of delivery has a significant effect on hematologic values. Only a rare parameter showed differences based on gender. The cord blood complete blood cell count has the potential for providing relevant clinical information for managing neonatal patients.