Magnitude of Red Blood Cell Alloimmunization Among Pregnant Women Attending Antenatal Care at Wolaita Sodo University Comprehensive Specialized Hospital, Southwest Ethiopia.

Background: Maternal red cell alloimmunization occurs when a woman's immune system becomes sensitive to unfamiliar red blood cell antigens. This leads to the production of alloantibodies, which can have serious implications for the fetus and newborn. However, there is a lack of comprehensive information about the extent of red cell alloimmunization in underdeveloped countries like Ethiopia. Therefore, this study aimed to determine the magnitude of red cell alloimmunization among pregnant women attending antenatal care at Wolaita Sodo University Comprehensive Specialized Hospital from September 01 to November 30, 2022.

Methods: In this institutional-based cross-sectional study, 422 pregnant women were participated and recruited using a systematic random sampling technique. Data on sociodemographic characteristics, obstetric history, and other clinical information were collected using structured questionnaires through face-to-face interview. Blood grouping and indirect antihuman globulin tests were performed. The relationship between red cell alloimmunization and the independent variables was determined using the chi-square test. P-value <0.05 was considered statistical significance.

Results: In this study, the blood group distributions among the participants were as follows: O, 177 (41.9%); A, 124 (29.4%); B, 76 (18%); and AB, 45 (3.86%). Among the pregnant women included in the study, a total of 51 (12.08%) were identified as RhD-negative. Out of these RhD-negative women, 5 (9.8%) were found to have developed alloimmunization with red blood cell antigens. Miscarriage and post-partum hemorrhage were found to be important factors associated with the occurrence of red cell alloimmunization in these women.

Conclusion: This study showed that one out of ten pregnant women was alloimmunized. Therefore, antenatal blood grouping and indirect antihuman globulin screening should be performed routinely to manage and minimize the undesirable outcomes of alloimmunization during pregnancy.