Introduction
Information and guidance for transfusion of pediatric and neonatal patients remained unchanged between the 2019 and 2025 versions of the AABB Association Bulletin “Recommendations on the Use of Group O Red Blood Cells.”1,2 The bulletin acknowledged the ease of using group O red blood cells (RBCs) for neonates since one RBC unit could provide aliquots for multiple recipients and using group O blood avoids additional testing to ensure compatibility with any maternal ABO antibodies. However, there were no recommendations for use of group O units in children, and data on current use in these patients were not given. A retrospective, multi-institution pediatric study was conducted to investigate group O blood usage, especially for non-group O patients, and to determine pediatric transfusion trends.3
Study Population
Eight U.S.-based institutions serving pediatric populations compiled electronic health record data for age, sex, diagnosis, blood type and transfusion information from January 1, 2015, to December 3, 2019. Four sites, collectively called Cohort O, only collected data on group O transfusions to patients of all groups (O, A, B, AB). The other four sites, called Cohort Z, collected transfusion data for all donor and recipient blood groups.
Study Results
Of 52,731 transfusions to non-group O (A, B, and AB) recipients, 67% were group O blood. The most frequent transfusions were in the diagnostic categories of cardiovascular disorders (22%), sickle cell anemia (15%), cancer (13%), neonates (12%), and benign hematology (10%).
Sixty-two percent of transfusions to non-neonate (> 4 months of age) non-group O recipients were group O RBCs, while the rest were group-specific. The diagnostic categories with the highest percentages of transfusions of group O blood were sickle cell anemia (90%), neonates (85%), trauma (67%), and cardiovascular disorders (62%). For sickle cell anemia, the heavy use of group O RBCs was felt to be due in part to the preferential antigen screening of these products because they can be used for patients of any ABO group.
Four hospital sites had a policy of transfusing only group O RBCs to all neonates regardless of blood type. For the remaining four hospital sites, which had a policy of giving group-specific transfusions, 59.5% of the group O RBC transfusions were to non-O recipients, making only 40.5% group-specific.
Of the 128,770 transfusions to Rh(D) positive patients, 26% were Rh(D) negative blood. Categories accounting for a large proportion of transfusions of Rh(D) negative blood to Rh(D) positive patients were neonates, cardiovascular disorders, and sickle cell anemia.
Twenty-one percent of transfusions to group O Rh(D) positive patients were group O Rh(D) negative RBCs. The most common category for these transfusions was infants over 4 months old with a neonatal diagnosis. The second most common was sickle cell anemia.
Transfusions of group O Rh(D) negative RBCs generally increased over the study period, more than tripling for cardiovascular disorders.
There were only 75 transfusions of group O Rh(D) positive RBCs to Rh(D) negative patients. Males received 81% of these transfusions. Trauma (47%) and cancer (19%) were the most common indications.
Discussion and Summary
Limitations of this study included the reliance of patient categorization on the accuracy of discharge or admitting diagnoses, data from only major metropolitan areas, and data from some sites on only group O RBC transfusion. Nonetheless, the results showed that the majority of group O RBCs are given to non-group O patients and that many transfusions to Rh(D) positive patients are Rh(D) negative blood. These findings are consistent with studies showing high proportions of group O Rh(D) negative RBC units being given to adults who are not group O Rh(D) negative.4-6 To address the resulting shortages, this article suggests several options. Development of a safe and practical policy for giving type-specific blood to neonates would be helpful. For sickle cell patients, the aforementioned AABB bulletin recommends that hospitals maintain an inventory of CEK-negative Rh(D) positive units to reduce the use of group O Rh(D) negative units for group O Rh(D) positive patients. Small studies suggest that low-titer group O whole blood may improve survival in pediatric patients with severe hemorrhage, and group O positive blood for this purpose is being considered.
References
1. Home – Association for the Advancement of Blood & Biotherapies [Internet]. Bethesda (MD): Association for the Advancement of Blood & Biotherapies; [cited 2025 Jun 2]. Association Bulletin #19-02; 2019 Jun 26. In: Internet Archive Wayback Machine [Internet]. San Francisco (CA): Internet Archive; [cited 2025 Jun 2]. [12 p.]. Available from: https://web.archive.org/web/20220401072925/https://www.aabb.org/docs/default-source/default-document-library/resources/association-bulletins/ab19-02.pdf?sfvrsn=39274f3e_0
2. Home – Association for the Advancement of Blood & Biotherapies [Internet]. Bethesda (MD): Association for the Advancement of Blood & Biotherapies; c2025. Association Bulletin #19-02; 2025 Apr [cited 2025 May 31]; [12 p.]. Available from: https://www.aabb.org/docs/default-source/default-document-library/resources/association-bulletins/ab19-02.pdf
3. Annen K, Andani S, Bosma G, Abbott D, Arinsburg S, Nguyen F, et al. O blood usage trends in the pediatric population 2015-2019: A multi-institutional analysis. Transfusion. 2025;65:676-83.
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5. Virk MS, Lancaster D, Quach T, Lim A, Shu E, Belanger G, Pham TD. Optimizing O-negative RBC utilization using a data-driven approach. Transfusion. 2020;60:739-46.
6. Dunbar NM, Yazer MH; OPTIMUS Study Investigators on behalf of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative. O- product transfusion, inventory management, and utilization during shortage: the OPTIMUS study. Transfusion. 2018;58:1348-55.
