Provision of KEL 1‐negative blood to obstetric patients: a 3‐year single‐institution retrospective review

Background KEL 1 alloimmunization is a major cause of hemolytic disease of the fetus and newborn ( HDFN ). While select countries have guidelines for preventing transfusion‐associated KEL 1 alloimmunization, the U nited S tates does not. B eth I srael D eaconess M edical C enter instituted a policy in A pril 2009 whereby women not more than 50 years of age on the obstetric service were transfused KEL 1‐negative red blood cells ( RBC s). We sought to determine compliance and impact for prevention of KEL 1 alloimmunization and HDFN . Study Design and Methods All women not more than 50 years of age without anti‐ K transfused RBC s during an obstetric admission from A pril 9, 2009, to A pril 9, 2012, were identified (227). Adherence to policy, factors contributing to nonadherence, and subsequent impact were evaluated. For comparison, all cases of anti‐ K detection in women not more than 50 years of age admitted to nonobstetric services and all cases of transfusion‐associated KEL 1 alloimmunization in women not more than 50 years of age during the 10 years prior were identified. Results Eighty‐four percent received only KEL 1‐negative units. Three (1.3%) women not more than 50 years of age on the obstetric service were identified with anti‐ K , while 17 (1.5%) women not more than 50 years of age on nonobstetric services had anti‐ K detected; only five of 20 had a prior RBC transfusion. In the 10 years prior, there were 27 cases of transfusion‐associated KEL 1 alloimmunization in women not more than 50 years of age. There were no cases of KEL 1 HDFN in either period. Conclusion Although the findings demonstrate feasibility of providing KEL 1‐negative RBC s to women of childbearing potential, evidence for clinical benefit is lacking. The low prevalence of KEL 1 in blood donors, the lack of significant differences in alloimmunization rates, and no cases of HDFN during the study period questions the clinical benefit of such a policy.