Loyola University Chicago Willowbrook, Illinois, United States
Background/Case Studies: Intrauterine transfusion (IUT) is an intervention by which blood products are transfused into fetal vasculature, most commonly the umbilical vein, via ultrasound-guided needle. The most common indication for IUT is severe fetal anemia, often as a result of HDFN. Though the incidence of HDFN has fallen since the widespread use of anti-RhD immune globulin (RhIG) in pregnancy, there remains an estimated 3/100,000 and 80/100,000 cases of HDFN in the United States yearly because of red cell alloimmunization by Rh(D) and other clinically significant antibodies. The use of large volumes of type O Rh(D) negative blood in intrauterine transfusion may obscure true fetal ABO and antigen type for months after transfusion, complicating the workup up of further transfusions in the neonatal period.
Study
Design/Methods: Patient clinical data was abstracted from the electronic medical record. Blood bank testing was performed through the in-hospital blood bank. Advanced antibody identification was performed at a regional reference laboratory.
Results/Findings: A 40-year-old B-negative gravida 2 para 0101 female with a history of anti-C and anti-G alloimmunization underwent intrauterine fetal transfusion for the treatment of HDFN in one of two gestating dichorionic diamniotic twins. In total, Twin B received three intrauterine transfusions of irradiated O-negative blood at 29 weeks, 31 weeks, and 34 weeks gestational age. Twin A was unaffected and did not undergo transfusion. At birth, the antibody screen of the mother and both twins redemonstrated the presence of anti-C with possible anti-G IgG. Twin B typed O-negative, and Twin A typed A-negative. Antigen typing of Twin B showed C-negative red cells. One month after birth, repeat type and screen from Twin B showed an ABO/Rh type discrepancy (Table 1), and antigen typing showed mixed-field reaction to C antisera. Twin B was typed as B-positive with C antigen-positive red cells, with an additional population of O-negative, C antigen-negative red cells. Conclusions: Our case describes a neonate with a history of HDFN and multiple intrauterine transfusions changing ABO/Rh type and C-antigen status at one-month post-partum. This is a complex transfusion scenario which must consider red cell antigens from both the donor and recipient, as well as vertically transmitted antibodies from the mother. If further transfusions were required in this case, we would transfuse ABO/Rh-compatible, C-negative blood. Consideration of RhIG administration in this case is also complicated by the initial blood type of the twins.
Importance of research: When reported at conferences or in journals, complex transfusion cases serve as a resource for transfusion teams who encounter a similar clinical scenario. In addition, this blood type discrepancy is a predictable outcome of multiple intrauterine transfusions but has not been thoroughly documented in the literature.
