The administration of intravenous immunoglobulin (IVIG) in pregnancies at high risk of developing severe hemolytic disease of the fetus and newborn (HDFN) due to blood type incompatibility could significantly delay the onset of red blood cell destruction (hemolysis) and decrease complications, according to a recently published study in SMFM 2024 Pregnancy Meeting.
What is HDFN?
Hemolytic disease of the fetus and newborn (HDFN) is an immune-mediated red blood cell (RBC) disorder that occurs when a baby’s RBCs break down quickly, which is called hemolysis. HDFN is caused by a mismatch between a mother’s and her baby’s blood type (A, B, AB, or O) or Rhesus (Rh) factor (Rh-positive or Rh-negative) during pregnancy. Numerous antibodies to RBC antigens can be linked to HDFN, such as those from the ABO and Rh blood group systems.
Pregnancies in which the mother is Rh negative and the fetus is Rh positive are considered to be at high risk for HDFN. In this condition, maternal antibodies destroy the red blood cells of the fetus, leading to complications such as anemia requiring intrauterine transfusions, increased bilirubin levels leading to permanent neurological damage and in some cases, death.
Learn more about HDFN therapies
A recent systematic review aimed to determine the efficacy of maternal IVIG administration in delaying the gestational age (GA) at the first intrauterine transfusion (IUT) and mitigating the onset of severe HDFN.
The study involved an extensive search of Medline, Embase and the Cochrane Library until June 2023. The focus was on pregnancies marked by Rh antigen incompatibility, characterized by either a previous fetal or neonatal death due to HDFN or the need for IUT before 24 weeks’ gestation in the prior pregnancy.
Cases included pregnancies where IVIG was administered to delay IUT, while controls represented pregnancies receiving IUT only. Individual patient data (IPD) were obtained, and authors were contacted for missing data. The primary outcome measured was the GA at the first IUT.
In all, 11 studies, covering 90 controls and 97 cases, showed that patients who received IVIG require IUTs later in the pregnancy than patients who received IUTs alone. At the time of the first IUT, the hemoglobin level was significantly lower in the IUT-only group than in the IVIG group.
The GA at delivery also showed a significant difference, with the IUT-only group experiencing earlier deliveries compared to the IVIG group. However, between the two groups, no significant differences were observed in the number of IUTs, hemoglobin levels at birth, or bilirubin levels at birth.
“IVIG treatment in pregnancies at risk of severe early HDFN seems to have a potentially clinically relevant beneficial effect on the course and severity of the disease,” the authors concluded.
