Red blood cell alloimmunization in pregnancy during the years 1996-2015 in Iceland: a nation-wide population study

• Published in: Transfusion
• Main Authors: Bollason, Gunnar, Hjartardottir, Hulda, Jonsson, Thorbjorn, Gudmundsson, Sveinn, Kjartansson, Sveinn, Halldorsdottir, Anna Margret
• Other Authors: 1 Univ Iceland, Fac Med, Reykjavik, Iceland 2 Landspitali Univ Hosp, Dept Obstet & Gynecol, Reykjavik, Iceland 3 Landspitali Univ Hosp, Blood Bank, Reykjavik, Iceland 4 Landspitali Univ Hosp, Dept Pediat, Reykjavik, Iceland, University of Iceland, Faculty of Medicine; Reykjavik Iceland, Department of Obstetrics and Gynecology; Landspitali University Hospital; Reykjavik Iceland, Blood Bank, Landspitali University Hospital; Reykjavik Iceland, Department of Pediatrics; Landspitali University Hospital; Reykjavik Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2017
• Subjects: Blóðflokkar; Meðganga; Nýburar; OAG12; BAB12; PED12; Rho(D) Immune Globulin; Erythroblastosis; Fetal; Infant; Newborn; Rho; Iceland
• Online Access: http://hdl.handle.net/2336/620362; https://doi.org/10.1111/trf.14262

To access publisher's full text version of this article click on the hyperlink below BACKGROUND: Red blood cell (RBC) alloimmunization during pregnancy is still a major problem. Historically, anti-D antibodies are most likely to cause severe hemolysis, but other antibodies are also important. In Iceland, postnatal RhIg prophylaxis was implemented in 1969, universal RBC antibody screening was implemented in 1978, but antenatal RhIg prophylaxis is not yet routine. STUDY DESIGN AND METHODS: This nation-wide population study gathered data on alloimmunized pregnancies in Iceland between 1996 and 2015. Blood bank alloimmunization data were linked to Icelandic Medical Birth Registry data. RBC antibodies were classified as either clinically significant or clinically nonsignificant. RESULTS: In total, 912 positive antibody screens from 87,437 births were identified (1.04% prevalence). The most frequent antibodies were anti-M (19.4%), anti-E (19.0%), and anti-D (12.5%). Anti-D prevalence among D-negative mothers was 1.1%. Icelandic Medical Birth Registry data were available for 881 (96.6%) pregnancies. In the clinically significant group (n = 474), anti-E (27%) and anti-D (20%) were most common, whereas anti-M was most frequent (53%) in the clinically nonsignificant group (n = 407). Mothers in the clinically significant group were older, more often multigravidae, had more abortions and stillbirths, and had shorter gestational length. Newborns in the clinically significant group were less healthy, had lower weight and Apgar scores, and required more treatment. Among specificities in the clinically significant group, anti-D antibodies were most strongly associated with severe hemolysis. CONCLUSION: In this study, the prevalence of alloimmunization was similar to that in previous reports. Of all clinically significant antibodies, anti-D was most strongly associated with severe hemolysis, requiring phototherapy or exchange transfusions. Our data emphasize the importance of implementing an antenatal prophylactic RhIg program ...