Proportion of unsensitized Rh(D)-negative pregnant women delivered at Siriraj Hospital who received a complete course of anti-D immunoglobulin: An awareness problem?

Abstract

Background: Rh(D) alloimmunization prophylaxis should be administered to unsensitized Rh(D)-negative pregnant women. A routine antenatal dose and a postpartum dose for women that delivered an Rh(D)-positive neonate are recommended. Due to a very low prevalence of Rh(D)-negative blood type in Thai population, awareness of this specific management may be lacking. Objective: To determine the proportion of unsensitized Rh(D)-negative pregnant women that delivered at Siriraj Hospital who received a complete course of anti-D immunoglobulin and to determine the factors associated with the failure to achieve a complete administration as well as pregnancy and neonatal outcomes. Materials and Methods: Medical records of 133 unsensitized Rh(D)-negative pregnant women were reviewed to determine the proportion of cases receiving a complete anti-D prophylaxis. Possible reasons for missing anti-D administration were postulated. Comparison between cases receiving and not receiving antenatal anti-D prophylaxis was performed in terms of associated factors. Pregnancy and neonatal outcomes were compared between women who received complete prophylaxis and those who did not. Results: A complete anti-D prophylaxis was obtained in 71.4% of the women with antenatal dose given to 78.2%. Late antenatal care (OR 2.6, 95% CI 1.4 to 4.9) and late or no antenatal care at Siriraj Hospital (OR 7.1, 95% CI 2.8 to 17.9) were associated with missing antenatal anti-D administration. Desire for tubal sterilization and positive maternal Rh(D)-antibody in the third trimester appeared to be the causes of postpartum dose omission. Pregnancy and neonatal outcomes were comparable between women receiving and not receiving a complete anti-D prophylaxis. Conclusion: The proportion of unsensitized Rh(D)-negative pregnant women delivering at Siriraj Hospital who received a complete anti-D prophylaxis was 71.4%. Late antenatal care, late or no antenatal care at Siriraj Hospital, desire for tubal sterilization, and positive maternal Rh(D)antibody in the third trimester were associated with the incomplete Rh(D) alloimmunization prophylaxis.