A pregnancy affected by hemolytic disease of the fetus and newborn (HDFN) may progress uneventfully without the need for intervention or treatment in utero.
However, in the first trimester and up to 20 weeks of gestation, when pregnant women have very aggressive antibodies or there are other complications, intravenous immunoglobulin (IVIG) and plasmapheresis may be recommended to delay or potentially prevent fetal anemia.
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.
What is plasmapheresis?
Plasmapheresis, also known as plasma exchange, is used to treat a variety of conditions, including autoimmune diseases, blood toxins, neurological diseases and high levels of cholesterol. In HDFN-affected pregnancies, it involves extracting the mother’s blood and separating the plasma, which includes the antibodies that cause HDFN, from the blood cells, temporarily replacing it with saline or albumin while the plasma is cleansed in an apheresis machine.
The clean plasma is then put back into the body. This reduces the antibodies in the mother’s blood, stopping them from attacking the fetus’ red blood cells and helping to guard against the onset of fetal anemia.
Plasmapheresis is a temporary treatment, as the antibodies can be reproduced by the mother’s immune response to the fetus’ blood. There is no fixed protocol on the frequency of plasmapheresis, with several plasmapheresis treatments generally required, depending on the levels of antibodies in the mother’s blood. In more high-risk cases, it can be combined with IVIG.
Learn more about HDFN treatment and care
Benefits of plasmapheresis
In the first trimester and up to 20 weeks, pregnancies affected by HDFN —particularly in subsequent pregnancies following HDFN-related loss—can benefit from plasmapheresis by delaying the onset of fetal anemia and potentially delaying or avoiding the need for intrauterine transfusion (IUT). It can also help improve outcomes for the fetus.
Complications of plasmapheresis
The plasmapheresis procedure during pregnancy is considered generally safe for the mother and baby. However, side effects may occur for the mother, including dizziness, blurry vision, a drop in blood pressure, fatigue, stomach cramps, a cold feeling, an allergic reaction, bruising or a blood clot. These side effects are temporary, and their severity and duration vary from person to person.
Plasmapheresis and IVIG
The combination of plasmapheresis and IVIG is recommended in cases where the risk is high for the HDFN-affected fetus. This combined treatment method has been shown to reduce antibody titers, delay IUT and help avoid fetal death.
