Comparison of Ex Utero and In Utero Cord Blood Collection Methods: Canadian Blood Services’ Cord Blood Bank
Bibliographic record
Abstract
Cord blood stem cells can be collected using two common techniques: ex utero cord blood collection and in utero cord blood collection. The Canadian Blood Services’ Cord Blood Bank (CBS’ CBB) has operated using both models since September 2013 at The Ottawa Hospital, Civic and General Campuses in Ottawa, Canada. This study compared the two models to evaluate the optimal collection model for the cord blood bank. There are multiple factors that influence a successful collection and both models pose different challenges. A retrospective analysis comparing ex utero and in utero collections with respect to volume, total nucleated cell count (TNC), bankability, quality events reported, and contamination rates was performed for cord blood (CB) units collected between September 30, 2013, and December 8, 2017. Further analysis was conducted with respect to the influencing factors for both collection models, such as hospital engagement and training. A total of 8,705 CB units were collected over a 5-year period: 4,776 (55%) and 3,929 (45%) CB units were collected using ex utero and in utero collection methods, respectively. The ex utero model produced 4,464 (93%) units that met acceptable volume; 1,113 units for production (23.3% eligible unit rate), a TNC median of 1.76 × 109, with a bankable rate of collections of 17% and a reported quality event rate of 23%. The in utero model produced 3,305 (84%) units that met acceptable volume; 647 units for production (16.5% eligible unit rate), a TNC median of 1.77 × 109, with a bankable rate of collections of 12% and a reported quality event rate of 53%. Contamination rates were 0.15% and 0.41% for ex utero and in utero, respectively. Results indicate that the ex utero collection model using dedicated CBS CBB staff performed better than the in utero model. The ex utero collection method resulted in more qualifying units stored, lower contamination rates, and fewer quality events compared with the in utero model. Effective December 2017, CBS’ CBB no longer operates the in utero collection site and maintains an ex utero model at all collection hospitals.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.009 | 0.027 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.004 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".