Frequency and Types of Red Cell Alloantibodies in Pregnant Females

Abstract

Introduction: Maternal isoimmunization, also called alloimmunization, occurs when immune system of a pregnant female is sensitized to foreign RBC surface antigen producing immune process. This maternal blood when goes to fetal circulation, causes immune reaction and disease in case of maternal and fetal blood group differences.

Aims & Objectives: To find out the frequency and types of red cell alloantibodies among females presenting to antenatal care and recognize risk factors for alloimmunization.

Place and duration of study: This cross-sectional descriptive study was carried out at Antenatal Clinic of Shaikh Zayed Hospital, Lahore from 1^st January 2013 to 31^st August 2013.

Material & Methods: Pregnant females with at least one previous pregnancy were typed for ABO and Rh antigens. They were screened and typed for red cell alloantibodies. Detailed history was taken to explore for the risk factors. SPSS version 20.0 was used for data analysis, frequencies of different alloantibodies, blood groups and risk factors reported as percentages, age and gravidity in mean±s.d.

Results: Out of 200 enrolled cases, 6(3%) had alloantibodies. Of the positive cases, anti-D was found in 3(50%), anti-C in 2(33.33%) and anti-Kell in 1(16.67%). Commonest risk factors were history of peripartum hemorrhage and gynecological procedures. In Rh-negative cases, disparity of spouse Rh group was also main factor.

Conclusion: The most common culprit antibody for alloimmunization was anti-D followed by anti-Kell and anti-C. Commonest risk factor for alloimmunization was pregnancy related bleeding and gynecological procedures. Large population-based studies are required to assess true magnitude of the problem.