Why Do Umbilical Cord Blood Units Fail to Qualify for Public Banking?

Background:  The goal of the Carolinas Cord Blood Bank (CCBB), a public cord blood (CB) bank, is to procure quality cord blood units (CBU) for use in hematopoietic stem cell transplantation. The banking process is comprised of donor screening, collection, processing, cryopreservation and testing. At each step, CBU eligibility is determined and units not meeting specifications are discarded. We explored reasons for CBU disposal to identify strategies to maximize the number of successfully banked CBUs.

Study design and methods:  The CCBB database was retrospectively analyzed to characterize and quantify reasons CBUs were ineligible for banking. The reasons for discard were collated, assigned to a step on a process chain and assigned to a category. Specifications for banking included a minimum volume of 40ml (to 2005) and 60ml (to present), a preprocessing total nucleated cell count (TNCC) of 1x10⁹cells and a post processing viability of >90%.

Results: From 1/1998-8/2012, 109,177 total CBU donors registered in the database. Of these, 34% did not have CBUs collected because of unavailable collection staff, placental/cord damage or CB clot, among other reasons. A total of 71,618 CBUs were collected, 40,986 (57%) of which were shipped to the processing lab.  Twenty-two percent of the CBUs sent for processing were subsequently discarded.  Time points for discard of collected CBUs were: 43% before processing, 5% during processing and 7% after cryopreservation. Reasons for disposal of 77,149 registrations or CBUs (Table 1) included 40% for low TNCC, 23% for low volume, 2% for low viability, and 0.7% for failed sterility.  

Conclusion:We identified reasons for banking failures in a large public CB bank.   While small volumes/low TNCC represented the major reasons for failure of collected CBUs to be banked, other factors influenced the failure to collect CBUs from recruited volunteer donors. Improving MD and technician training to increase the volume of collections and awareness of collection procedures in regards to placenta and cord handling, as well as expanding program collection hours, could impact the overall banking success.  The financial impact of CBU losses will also be discussed.

Dispose Reason	N	% of disposed CBU/barcodes (n=77149)
Low TNCC	30815	39.9
Low Volume	17415	22.6
Placenta issue	7279	9.4
Not collected	5356	6.9
Maternal history problem	3817	4.9
Cord issue	3693	4.8
Low Viability	1404	1.8
Processing issues	1159	1.5
Cord clot	872	1.1
Maternal Sample Problem	750	1.0
Consent refused/withdrawn	567	0.7
Donate/research	553	0.7
Data Missing	546	0.7
Failed CBU Sterility	529	0.7
Subsequent Med Info	476	0.6
CBU Expired	364	0.5
Delivery complication	326	0.4
Training unit	307	0.4
Collection kit issue	301	0.4
Cryopreservation	251	0.3
Abnormality in baby	232	0.3
Potency/CFU	88	0.1
NRBC >50%	49	0.1
TOTAL	77149