Introduction: The advent of RhD immunoglobulin prophylaxis to prevent maternal RhD alloimmunization has reduced the incidence of this condition and its associated poor outcomes. Consequently, non-D Rh antibodies now account for a greater proportion of alloimmunized pregnancies. These antibodies have been the subject of comparatively little research. This study investigated the incidence and clinical outcome of pregnancies affected by non-D Rh alloimmunization at an Australian tertiary maternity service.
Material and methods: This was a retrospective study of all pregnancies with non-D Rh antibodies (namely anti-C, -E, -c, -e, -Cw as well as the compound antibodies anti-CD, -cE and -ce) managed at the Royal Women's Hospital, Victoria, Australia, from 2009 to 2013 inclusive. Information collected included maternal demographics, details of the antibodies, course of the pregnancy and neonatal outcomes.
Results: During the study period, 115 non-D Rh alloimmunized pregnancies were identified in 102 mothers. Forty-nine pregnancies reached the critical titer (> 16) from non-D Rh alone and 11 fetuses received intrauterine red blood cell transfusion. Labor was induced or cesarean section performed in 38 cases. Forty-three neonates were admitted to the special care nursery and 59 received phototherapy. Nine received treatment for anemia and 10 neonates received intravenous immunoglobulin.
Conclusions: Non-D Rh alloimmunization is a relatively uncommon complication of pregnancy, occurring in only .33% of pregnancies in the study period. It can lead to significant fetal/neonatal morbidity (and may lead to mortality). The most severe outcomes (including perinatal deaths) were mostly associated with the compound antibodies anti-CD and anti-cE, or a non-D Rh antibody in conjunction with anti-D.
Keywords: Rh; alloimmunization; blood group antibody; hemolytic disease of the fetus/newborn; non-D; pregnancy.
© 2019 Nordic Federation of Societies of Obstetrics and Gynecology.