Data Quality Improvements for Search & Match Service

Following the migration to the new Data Manager, you may have noticed differences in the number of donor and cord blood unit records returned in Search & Match. These changes are mainly the result of stricter data validation rules and the discontinuation of listings by a small number of organisations.

WMDA members and the WMDA Office have invested considerable effort in improving the quality of our shared data resources. Together, we worked to remove outdated information, including deprecated HLA codes, and to improve the completeness and consistency of listed data. While significant progress was made, some donor and cord blood unit records did not meet the new validation requirements and were therefore not migrated to the new database.

Organisations no longer fully listed
The following organisations have no records available in Search & Match:

ION | Organisation
3034 | Bone Marrow Registry Nigeria
6579 | Cleveland Cord Blood Center
4068 | Chaim Sheba Medical Center
2197* | China Marrow Donor Program
4857 | Celebration Stem Cell Centre
8405* | National Institute Organ Tissue Blood Management Korea CORD

*WMDA is actively engaging with these registries to define a mutually accepted path forward.

Overall migration impact
Of the records that were processed during the migration:

211,553 donor records were rejected (due to deprecated/missing HLA, age >60 and/or invalid serology), representing 0.49% loss;

65,461 CBU records were rejected (due to missing processing, viability and/or freeze data), representing 8.80% loss; and

overall, 43,626,851 of 43,903,865 processed records were retained, representing an overall rejection rate of only 0.63%.

These changes may explain why a donor or CBU that previously appeared in a search is no longer returned, or why the number of results differs from searches performed before the migration (7 July 2026) or on another platform. WMDA is working directly with the most affected organisations to help them correct and resubmit records where possible.

Search coordinators who are concerned that relevant donors or CBUs may be missing from a search are encouraged to contact affected listing organisation directly for information about available donors or CBUs for their patient.

Please contact support@wmda.info or use the WMDA Support Portal if you have questions about a specific search, record or affected organisations.