Immune Erythrocyte Alloantibodies among Pregnant Women Attending an Antenatal Clinic in a Tertiary Health Facility, Benin City, Nigeria

Abstract

BACKGROUND: Maternal alloimmunization is associated with adverse outcomes such as hemolytic disease of the fetus and newborn. At‑risk pregnant women include those with previous multiple gestations or multiple blood transfusions. This study aimed to determine the proportions and specificities of irregular maternal alloantibodies among antenatal attendees at a federal teaching hospital in Nigeria. An understanding of the pattern of alloimmunization, associated morbidities, and attendant risk factors will guide improved antenatal/perinatal health planning. MATERIALS AND METHODS: A hospital‑based, cross‑sectional survey was conducted among 150 pregnant women. Data on parity, transfusion history, and other clinical details were obtained with an interviewer administered questionnaire. ABO/Rh D blood groups and hemoglobin phenotypes were retrieved from their antenatal records and confirmed during the study. Alloantibody screening and identification and other serological tests were subsequently performed. Association of independent parameters with other variables was tested using Chi‑square analysis or Fisher’s exact as appropriate. Level of statistical significance was set at 5% confidence (P = 0.05). RESULTS: Most of the participants (60%) were in their third trimester, while 9.3% were in first trimester of pregnancy. Ninety‑one percent of the participants (90.7%) were blood transfusion naïve. Seven of the participants (4.7%) had positive alloantibody screens, of which two (1.33%) were clinically significant maternal alloantibodies (Anti‑D and Anti‑Lub). No statistically significant association was observed between alloimmunization and variables such as gestational age, parity, hemoglobin phenotype, previous blood transfusions, and Rh D negativity. CONCLUSIONS: The authors recommend routine alloantibody screening for at risk pregnancies.