Background: although the amount of umbilical cord blood(UCB) is the most important
factor for successful UCB transplantation, optimal collection method of UCB is not
established yet, especially in Cesarean section. This study was performed to determine
the optimal collection method of UCB.
Methods: Collection of UCB was performed in 71 full-term deliveries. In 34 vaginal
deliveries, UCB was collected by gravity and uterine contraction before placental
expulsion, and by gravity and milking after placental expulsion. In 37 Cesarean sections,
collection was made by gravity and milking after placental expulsion, combined with(6
cases) or without(31 cases) preceding collection by syringe aspiration from the umbilical
vein before placental expulsion. Salvage collection was made after usual collection.
Results :
1) Mean volume of collected UCB was 112.6土27.9mL(range: 72∼220mL) in vaginal
delivery, 79.1 ±28.9mL(range: 25∼131mL) in Cesarean section when collection was
started after placental delivery, and 111.3±25.0mL(range: 74∼152mL) in Cesarean section
when collection was started before placental delivery.
2) Mean volume of collected UCB in salvage collection was 4.6±2.7mL(range: 1.0∼
12.0mL) in puncture and aspiration method, and 7.4±3.7mL(range: 1.7∼ 15.3mL) in flush
and drain method.
3) There was no bacterial growth in collected UCB culture.
4) Mean number of nucleated cells was 11.9±6.4×10⁸(range: 1.9∼29.3×
10⁸) before centrifugation, and 11.2±5.7×10⁸(range: 2.0∼20.9
×10⁸) after centrifugation; mean number of CD34⁺cells
was 9.8±4.9×10⁶(range: 3.3∼17.1×10⁶).
5) Variables correlated with volume of UCB were placental weight(f=0.0022), maternal
age (P=0.03), and gestational period(P=0.04).
Conclusion: Collection of UCB should be started before placental expulsion, especially
in Cesarean section, and significant amount of cord blood can be collected also after
placental expulsion.

Keywords: Umbilical cord blood, Collection, Transplantation, Cesarean section