Prevalence of Red Cell Alloantibodies in Pregnant Women

Background: Red cell alloimmunization results genetic disparity of Red Blood Cell (RBC) antigen between the fetus and mother in pregnancy. The development in red cell alloimmunization in pregnancy occurs as a consequence of transplacental movement of fetal RBC either during delivery, miscarriage, ectopic pregnancy or during invasive procedure like amniocentesis. Alloimmunization is significant especially when it involves a clinically significant alloantibody that causes hemolytic transfusion reaction and fetal anemia leading to hemolytic disease of fetus and newborn (HDFN). Aim: To identify and estimate the frequency of red cell alloimmunization among Rh-D negative and Rh-D positive pregnant women as well as establishing a screening protocol and management protocol to reduce the rate of haemolytic diseases of fetus and newborn. Material and methods: This is a prospective study of antenatal mothers for a period of one year and nine months conducted in Transfusion Medicine Department of SCB Medical College & Hospital, Cuttack. A total of 362 pregnant mothers irrespective of their gestational period and meeting the eligibility criteria and giving consent were included in our study. Blood grouping and Rh-typing, Antibody screening, Antibody Identification were done by Conventional Test Tube (CTT) method, 3-cell panel and 11-cell panel respectively. Titer of the identifying antibodies was done by serial, two fold double dilution method using CTT. Results: Out of 362 pregnant women, 13(3.6%) women showed positive antibody screening. A total number of 14 antibodies were identified. The Red cell allo-immunization among Rh-D negative women and Rh-D positive women were 4.42% and 2.2% respectively. The antibodies identified were anti-D, anti-c, anti-E, anti-C and anti-Leᵃ. Both single and multiple antibodies were detected in our study. We found 0.59% primigravida showing positive antibody screening. The antibody titer in two cases was above the critical level. Conclusion: The alloimmunization was found not only in Rh-D negative but also in Rh-D positive pregnant women. So universal antenatal screening in pregnant mothers should be initiated. The titer of the antibody should be closely monitor and manage the fetus accordingly.