(P-TS-105) Reduction in Neonatal Direct Antiglobulin Test Utilization Through Protocol Revision

Background/Case Studies: ABO incompatibility arises when a mother with blood type O delivers an infant with a non-O blood type, which can result in isoimmune hemolytic disease of the newborn, often presenting with hyperbilirubinemia and a positive direct antiglobulin test (DAT). As a precaution, many institutions routinely perform a DAT on infants born to group O mothers. In practice, neonatal ABO/Rh typing and DAT are often bundled in a single order set, resulting in DAT testing even when the infant is also group O. To assess the utility of this practice, we retrospectively reviewed 18 months of data from a community hospital, identifying 571 group O mother-infant pairs. Among the 453 pairs without Rh incompatibility, all DAT results were negative. Based on these findings, we revised our blood bank protocol to omit DAT testing for infants who are group O positive born to group O positive mothers.

Study

Design/Methods: Following the protocol change, neonatal blood typing results were reviewed to identify infants who were group O positive. If the mother was also group O positive and had no clinically significant alloantibodies, a DAT was not performed. Data from the first nine months after implementation were collected and analyzed to assess the impact of the revised practice. Infants who were anticipated to require blood transfusion were excluded from the study, as they were enrolled in a separate protocol in which blood typing, DAT, and antibody screening were performed regardless of blood group.

Results/Findings: We identified 286 mothers who were group O positive and had no clinically significant alloantibodies. Among them, 159 infants (55.6%) were also group O positive and eligible for the revised protocol. DAT testing was requested by providers in 10 cases, and was inadvertently performed by the blood bank in an additional 12 cases. All 22 DAT results were negative. The rate of inadvertent DAT testing declined over time: 15.2% in the first three months post-implementation, 8.8% in the second three months, and 0% in the final three months. Overall, DAT testing was avoided in 137 of the 286 cases after the updated protocol was implemented, resulting in a 47.9% reduction in testing (Figure A).

Conclusions: Our targeted elimination of routine DAT testing in group O positive infants born to group O positive mothers without alloantibodies resulted in a significant reduction in unnecessary testing, and concurrent cost savings for the customer. This quality improvement initiative demonstrates a safe and effective strategy to optimize laboratory resource utilization.