A history of previous blood transfusions in alloimmunized pregnancies does not appear to significantly impact the risk or severity of hemolytic disease of the fetus and newborn (HDFN), according to a recently published abstract in Pregnancy.
The authors aimed to assess whether a history of previous blood transfusions in pregnant individuals could significantly increase the need for cerebral medium artery (MCA) Doppler monitoring or intrauterine blood transfusions (IUTs).
HDFN is a consequence of maternal exposure to non-self red blood cell (RBC) antigens. This exposure typically occurs during pregnancies, during which the fetuses carry different RBC antigens than the mothers, and during blood transfusions.
In emergency settings, there is often not enough O-negative blood available. Therefore, many emergency blood transfusions can lead to alloimmunization. This article sheds light on whether performing blood transfusions after alloimmunization significantly increases the risk of HDFN and its complications.
“ A single-center retrospective cohort study of alloimmunized singleton gestations with antibodies known to be associated with hemolytic disease of the fetus and newborn (HDFN) from 2018 to 2023,” the authors wrote. “We excluded pregnancies if the fetus was determined to be not at risk for HDFN either by negative paternal genotyping or negative invasive diagnostic testing,”
The single-center retrospective study included 76 pregnancies with alloimmunization in which 36 mothers had a previous history of blood transfusion, and 40 did not. Results showed that patients with a history of alloimmunization had a wider variety of antibodies than the other group. The most frequently observed antibody among patients with previous transfusions was anti-K, while anti-D was more common in patients without previous transfusions.
Researchers observed no significant differences in maximum antibody titer reached during pregnancy between both groups. Furthermore, both groups required MCA Doppler monitoring and IUTs in similar proportions.
“Patients who develop alloimmunization due to blood transfusion are more likely to present with a wider variety of antibodies but this does not impact the need for MCA Doppler monitoring or IUT in a clinically significant way,” the authors concluded.
