Red cell alloimmunization to rhesus antigen among pregnant women attending a tertiary care hospital in Oman

Objectives: The detection of maternal alloimmunization against red cell antigens is vital in the management of hemolytic disease of the fetus and newborn. We sought to measure the presence of allosensitization to Rhesus D (RhD) antibodies in antenatal women attending a tertiary care hospital and assess the fetal outcome in sensitized women. Methods: We conducted a retrospective review of pregnant Omani women who registered at the Sultan Qaboos University Hospital between June 2011 and June 2013. Pregnant women were tested for ABO blood type and were screened for RhD antigen and antibodies at their first antenatal clinic visit. In women who tested positive for the RhD antibodies, an antibody titer was performed to evaluate the severity of their case. Results: Data was available on 1,251 pregnant women who were managed and delivered at Sultan Qaboos University Hospital. The prevalence of RhD negative pregnant women was 7.3%. Blood group O was the most common followed by A, B, and AB. The rate of RhD negative alloimmunization was 10%, and anti-D was the most common antibody detected. There were no stillbirths or neonatal deaths. Postnatal transfusion was necessary for only one baby. Conclusions: The prevalence of RhD negativity was comparable to other Asian countries. Previous RhD alloimmunization and history of miscarriages were the most common maternal medical history.