Blood Group Antigen Matching Influence on Gestational Outcomes (AMIGO) study.
Red blood cell (RBC) antigen matching policies to prevent alloimmunization in females of childbearing potential (FCP) vary between centers. To inform transfusion centers responsible for making decisions about matching policies for FCPs, the causal stimulus of the antibodies implicated in severe hemolytic disease of the fetus and newborn (HDFN) must be determined.



We conducted a multinational retrospective study of women with offspring affected by severe HDFN requiring neonatal exchange transfusion and/or intrauterine transfusion. Mothers treated at centers that provide extended antigen-negative RBCs (MATCH, five centers) and those that do not (NoMATCH, nine centers) were compared.



A total of 293 mothers had at least one affected pregnancy: 179 at MATCH centers and 114 at NoMATCH centers. Most alloimmunization (83%) was attributed to previous pregnancy: 3% to transfusion (two cases at MATCH, six at NoMATCH centers) and 14% undetermined (both antecedent transfusion and pregnancy). Only 50 mothers had received transfusions; 13 had HDFN due to anti-K at MATCH and four at NoMATCH centers. Most (12/13, 92%) of the anti-K HDFN cases at MATCH centers had K+ paternal antigen status. Mothers at the MATCH centers do not appear to be protected from HDFN due to K, C, c, and E antibodies, although the low number of FCPs who received transfusions precluded drawing firm conclusions.



The causal stimulus of antibodies that cause HDFN is predominantly from previous pregnancy. Although extended RBC matching for FCPs may impart some protection from allosensitization, we were unable to show a positive effect, possibly because matching policies are not uniform and there was a small number of mothers who previously received transfusions.
Bloodworks Northwest & Department of Laboratory Medicine & Pediatrics, University of Washington, Seattle, Washington.
Meghan
M
Delaney
Clinical Immunology and Transfusion Medicine, Karolinska University Hospital and Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.
Agneta
A
Wikman
Sanquin - Leiden University Medical Centre, Center for Clinical Transfusion Research, Leiden, the Netherlands.
Leo
L
van de Watering
Sanquin - Leiden University Medical Centre, Center for Clinical Transfusion Research, Leiden, the Netherlands.
Henk
H
Schonewille
Sanquin - Leiden University Medical Centre, Center for Clinical Transfusion Research, Leiden, the Netherlands.
Jennie P
JP
Verdoes
University of Pittsburgh School of Medicine and the Institute for Transfusion Medicine, Pittsburgh, Pennsylvania.
Stephen P
SP
Emery
NHS Blood and Transplant, Oxford University Hospitals and National Institute for Health Research (NIHR) Oxford Biomedical Research Centre.
Michael F
MF
Murphy
Oxford University Hospitals, Oxford, UK.
Julie
J
Staves
Oxford University Hospitals, Oxford, UK.
Susanne
S
Flach
McMaster University, Hamilton, Ontario, Canada.
Donald M
DM
Arnold
Division of Transfusion Medicine, Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
Richard M
RM
Kaufman
Wing-Kwai and Alice Lee-Tsing Chung Transfusion Service, Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California.
Alyssa
A
Ziman
Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, Vermont.
Sarah K
SK
Harm
Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington, Vermont.
Mark
M
Fung
Department of Maternal Fetal Medicine, Baylor College of Medicine, Houston, Texas.
Catherine S
CS
Eppes
Department of Pathology and Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
Nancy M
NM
Dunbar
Regional Blood Transfusion Service, Swiss Red Cross, Basel, Switzerland.
Andreas
0000-0002-7942-6746
A
Buser
Department of Pathology and Laboratory Medicine, Emory University School of Medicine.
Erin
E
Meyer
Department of Hematology, The Royal Children's Hospital, Melbourne, Australia.
Helen
H
Savoia
Department of Hematology, The Royal Children's Hospital, Melbourne, Australia.
Padmakumari
P
Abeysinghe
McMaster University, Hamilton, Ontario, Canada.
Nancy
N
Heddle
Departments of Medicine and Laboratory Medicine & Pathology, University of Ottawa, University of Ottawa Centre for Transfusion Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
Alan
A
Tinmouth
McMaster University, Hamilton, Ontario, Canada.
Aicha N
AN
Traore
University of Pittsburgh School of Medicine and the Institute for Transfusion Medicine, Pittsburgh, Pennsylvania.
Mark H
MH
Yazer
D000328:Adult; D001789:Blood Group Antigens / Q000097:blood*; D001788:Blood Grouping and Crossmatching; D004899:Erythroblastosis, Fetal / Q000097:blood / Q000453:epidemiology; D005260:Female; D005331:Fetomaternal Transfusion / Q000097:blood / Q000453:epidemiology; D006801:Humans; D007518:Isoantibodies / Q000097:blood*; D011247:Pregnancy; D012189:Retrospective Studies
D001789:Blood Group Antigens; D007518:Isoantibodies