RESUMO
OBJECTIVE: This study was undertaken to compare 3 methods of collection of human umbilical cord blood. STUDY DESIGN: Seventy-five women with uncomplicated vaginal deliveries were divided equally into 3 groups. One of 3 cord blood collection methods was applied to each woman. Method 1 was collection of cord blood into a standard donation blood bag. Methods 2 and 3 used a syringe to perform a sodium chloride solution flush and drain, which included withdrawal of cord blood by a syringe until the delivery of the placenta, followed by flushing through a catheter one of the umbilical arteries with sodium chloride solution and collection of the cord blood either into an open sterile container (method 2) or into a standard donation blood bag (method 3). Analyses included comparisons among the 3 groups of volume collected, total number of white blood cells, and bacterial contamination rates (positive culture results). In addition a correlation was made between the different variables and the collected cord blood nucleated cells. RESULTS: Cord blood collection by the blood bag method (method 1), which is presently the standard clinical practice, resulted in a mean blood volume of 76.4 +/- 32.1 mL and a mean total white blood cell count of 835 +/- 507 x 10(6) cells. With collection methods 2 and 3, in which as much blood as possible was withdrawn by syringe while the placenta was still in utero followed by a second collection after infusion of the umbilical artery with sodium chloride solution, the mean volume collected was significantly higher (P <.05) at 174.4 +/- 42.8 mL and 173.7 +/- 41.3 mL, respectively, with significantly higher (P <.001) mean total white blood cell counts of 1624 +/- 887 x 10(6) cells and 1693 +/- 972 x 10(6) cells, respectively. A direct correlation was observed between the cord blood volume collected and placental weight, whereas no correlations were observed with maternal age, pregnancy duration, or the neonate's weight. Bacterial contamination was significantly higher (P =.04) in cord blood collections obtained by method 2 (48%) than by methods 1 (16%) and 3 (19%). CONCLUSIONS: The syringe-assisted sodium chloride solution flush collection method with a blood bag (method 3) was found to be the most effective method for human umbilical cord blood collection. This method doubles the total white blood cells collected with respect to current yields, which may make cord blood transplantation applicable for adults.
