Journal of Associated Medical Sciences (May 2017)
Screening of ABO, Rh typing and unexpected alloantibodies in pregnant women attending antenatal care at Sriphat Medical Center, Faculty of Medicine, Chiang Mai University
Abstract
Introduction: Pregnancy can stimulate a mother’s immune response to produce antibody to blood group antigens of fetal RBCs. Fetal RBCs with different blood group entering maternal blood circulation during pregnancy may stimulate maternal immune response. Maternal IgG anti-fetal RBCs can cross placenta to sensitize and destroy fetal RBCs causing hemolytic disease of the fetus and newborn (HDFN). Presently, screening of ABO, Rh typing and unexpected alloantibodies in pregnant women are routine tests for antenatal women. Therefore, the researchers were interested in studying the frequency of unexpected alloantibodies in pregnant women attending antenatal care at Sriphat Medical Center, Faculty of Medicine, Chiang Mai University. Objectives: To determine the frequency of ABO, Rh typing and unexpected alloantibodies in pregnant women attending antenatal care of Sriphat Medical Center, Faculty of Medicine, Chiang Mai University. Materials and methods: A total of 300 pregnant women attending antenatal care were tested for ABO, Rh typing and antibody screening. Antibody identification and autoantibody were performed on positive screening results. Results: ABO phenotyping revealed blood group O, B, A, and AB were 50%, 28%, 18.67%, and 3.33%, respectively. All samples were Rh positive. Positive antibody screening of anti-Lea and anti-Leb were found in two samples. Both were not autoantibody. These two antibodies showed 2+ agglutination at room temperature, 37 oC and anti-human globulin phases as were found in antibody screening. Conclusion: Anti-Lewis antibodies of both IgG and IgM were detected in this study. The IgG form may cause HDFN. Screening of alloantibodies in pregnant women, thus be helpful in monitoring one who is at risk of HDFN. Moreover, it is helpful for doctor to diagnose and plan for supportive care of HDFN. Journal of Associated Medical Sciences 2017; 50(2): 153-158. Doi: 10.14456/jams.2017.18
