Safety and feasibility of umbilical cord blood collection from preterm neonates after delayed cord clamping for the use of improving preterm complications

Background: Umbilical cord blood (UCB) is a new and convenient source of stem cells reported to be safe and effective in preventing and treating preterm complications. The initial processing step for this therapy involves cord blood collection and isolation of the mononuclear cell (MNC) layer. However, there is limited information regarding the feasibility and safety of cord blood collection in preterm infants, and whether cord blood cell quality and quantity are adequate for treating complications in preterm infants. UCB units from preterm infants are currently discarded due to safety concerns regarding collection and owing to the harvesting of inadequate volumes for banking. This study aimed to investigate the feasibility and safety of UCB collection following delayed cord clamping (DCC) for preventing and treating complications in preterm infants. Methods and Materials: Singleton preterm infants below 35 weeks gestation were assigned to two cohorts: cord blood collection and non-cord blood collection groups. Mortality and preterm complications in the two groups were compared to evaluate the safety of cord blood collection in preterm infants. The characteristics of the cord blood cells in preterm infants were investigated by comparing the cord blood parameters before and after processing with those of term infants born during the same period. Results: There were 90 preterm infants and 120 term neonates enrolled in this study. Compared to those of the term group, the preterm neonates had significantly less cord blood volume and fewer cell numbers. Nevertheless, the MNC number in the preterm group was 1.92 +/- 1.35x10(8) per kg, which fulfilled the previously reported targeted cell dose (5x10(7) cells/kg) suitable for application to improve preterm complications. There was no significant difference regarding complications in the preterm neonates with or without cord blood collection. Conclusions: The collection of UCB after DCC in preterm infants is feasible and safe. The cell numbers and quality fulfill the criteria for use in improving preterm complications. Cord blood MNCs from preterm neonates should be reconsidered as an ideal source for use in stem cell therapy for preterm complications.