title: Delayed clamping of the umbilical cord after delivery and implications for public cord blood banking.
abstract: BACKGROUND
  Public banking of umbilical cord blood units (CBUs) containing higher numbers of cells ensures timely engraftment after transplantation for increasing numbers of patients. Delayed clamping of the umbilical cord after birth may benefit some infants by preventing iron deficiency. Implications of delayed cord clamping for public cord blood banking remains unclear.
  
  
  METHODS
  CBUs collected by Canadian Blood Services at one collection site between November 1, 2014, and March 17, 2015, were analyzed. The delay in cord clamping after birth was timed and classified as "no delay," 20 to 60 seconds, more than 60 seconds, or more than 120 seconds.
  
  
  RESULTS
  Of 367 collections, 100 reported no delay in clamping while clamping was delayed by 20 to 60 seconds (n = 69), more than 60 seconds (n = 98), or more than 120 seconds (n = 100) in the remaining cases. The mean volume and total nucleated cells (TNCs) in units with no delay in clamping were significantly greater than mean volumes for all categories of delayed clamping (Tukey's test, p < 0.05 for each comparison). The proportion of units with more than 1.5 × 10(9) TNCs was significantly reduced when clamping was delayed (p = 5.5 × 10(-8) ). The difference was most marked for cords that were clamped more than 120 seconds after delivery (6.2% compared with 39%).
  
  
  CONCLUSIONS
  Delayed cord clamping greatly diminishes the volume and TNC count of units collected for a public cord blood bank. Creating an inventory of CBUs with high TNC content may take more time than expected.
authors.affiliation: Canadian Blood Services' Cord Blood Bank.|Blood and Marrow Transplantation, the Ottawa Hospital, and the Department of Medicine, University of Ottawa.
authors.forename: David S
authors.initials: DS
authors.lastname: Allan
authors.affiliation: Blood and Marrow Transplantation, the Ottawa Hospital, and the Department of Medicine, University of Ottawa.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Scrivens
authors.affiliation: Canadian Blood Services' Cord Blood Bank.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Lawless
authors.affiliation: Canadian Blood Services' Cord Blood Bank.
authors.forename: Karen
authors.initials: K
authors.lastname: Mostert
authors.affiliation: Department of Obstetrics and Gynecology, the Ottawa Hospital and the University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Oppenheimer
authors.affiliation: Department of Obstetrics and Gynecology, the Ottawa Hospital and the University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Walker
authors.affiliation: Canadian Blood Services' Cord Blood Bank.
authors.forename: Tanya
authors.initials: T
authors.lastname: Petraszko
authors.affiliation: Canadian Blood Services' Cord Blood Bank.
authors.forename: Heidi
authors.initials: H
authors.lastname: Elmoazzen
mesh_terms: D001771:Blood Banks; D003250:Constriction; D036861:Delivery, Obstetric / Q000379:methods*; D005260:Female; D005312:Fetal Blood / Q000637:transplantation*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D011247:Pregnancy; D014470:Umbilical Cord