Maternal sickle cell anemia and neonatal isoimmunization

Objective: To study the risk of alloimmunization in pregnant women with sickle cell disease (SCD) and of isoimmunization in their offspring. Method: Thirty mothers with SCD were studied and their 35 neonates (group 1) were compared with 538 infants of mothers without hemoglobinopathies (group 2). Result: Six mothers with SCD developed alloantibodies. There was no correlation with maternal age (P = 0.6), parity (P = 0.18) or blood transfusions (P = 0.4). The risk of alloimmunization by transfusion was 20%. Six neonates were isoimmunized, a higher incidence than in group 2 (P = 0.02; relative risk 3.07). Five had ABO incompatibility and only one had anti-c isoimmunization. All had reticulocytosis, jaundice and required phototherapy, one developed anemia but none required blood transfusion. Conclusion: Although alloimmunization was common in mothers with SCD and isoimmunization in their offspring, it was rarely due to non-ABO alloantibody. There was no significant neonatal morbidity.