Abstract
BACKGROUND: Maternal alloimmunization can lead to significant perinatal morbidity and mortality. The rate of maternal alloimmunization reported is varied across the studies conducted in India. A systematic review will help in understanding the overall prevalence of alloimmunization. Additionally, the study aimed at understanding the factors affecting the rate of maternal alloimmunization. METHODS: A search of original articles reporting rate of alloimmunization among antenatal women published in English language from India was performed in Scopus, Google Scholar, MEDLINE, and CINAHL databases. Two independent teams, each comprising two reviewers, extracted data from the eligible studies. Meta-analysis was performed for cumulative estimates by binary random-effects model using the restricted maximum likelihood method. RESULTS: Fourteen studies published between 2011 and 2023 were included. The pooled prevalence of maternal alloimmunization was 2.0 per 100 (95% CI: 1.5-2.5) among antenatal women, with significant heterogeneity across studies. Anti-D was the most frequently identified antibody (56.39%), followed by anti-D + anti-C (10.68%) and anti-E (5.71%). Higher risk of alloimmunization was observed in women with Rhesus D-negative blood group, multigravida status, history of blood transfusion, and bad obstetric history. CONCLUSION: Despite the availability of anti-D prophylaxis, over half of the alloimmunized women had anti-D antibodies, indicating potential gaps in prevention strategies. Further research is needed to understand these gaps and implement effective interventions to minimize this preventable cause of fetal and neonatal complications. For girls and women of reproductive age, providing prohylactic antigen-matched (Rh and Kell) red cell units when transfusion is needed may reduce the burden of red cell alloimmunization.