Treatments such as IVIG are often used for the management of hemolytic disease of the fetus and newborn (HDFN), according to a review conducted by specialists and published recently in BJOG: An International Journal of Obstetrics and Gynaecology.
At the onset of pregnancy, women typically undergo blood testing in order to evaluate their ABO blood group and the presence or absence of Rhesus (Rh) antigens. The five main Rh antigens found on RBCs are C, c, D, E and e. Of note, anti-D is the most common antibody associated with HDFN.
Read more about HDFN testing and diagnosis
When a pregnant patient is recognized as being RhD negative, she will undergo a noninvasive blood test to determine whether the fetus’s blood group is the same as the mother’s. In those cases in which the mother is RhD negative and the baby is RhD positive, the baby is considered to be at risk. In such scenarios, the newborn has inherited the D antigen from the father, which is known as Rh incompatibility. There are other RBC antibodies, such as anti-Kell and anti-Duffy, which may be linked to the development of fetal anemia as well.
Pregnant women at elevated risk for HDFN include those who have experienced at least one prior birth, as well as those who have experienced a sensitizing event, such as a fetomaternal hemorrhage during pregnancy, during the birth process, or after being transfused with incompatible blood.
In cases of earlier, more severe anemia, intrauterine transfusions (IUTs) may be needed, followed by an exchange transfusion after birth. IUT is associated with a small risk for loss of the pregnancy or preterm labor. In fact, if anemia is diagnosed later on in a pregnancy, early delivery may be recommended. Early delivery, however, is known to be linked to certain complications of premature birth.
Postnatal treatments for HDFN
When a woman with clinically significant antibodies delivers her baby, she should undergo a cord direct antiglobulin test (DAT). The use of DAT is intended to evaluate whether a newborn’s RBCs are coated with antibodies, as well as to assess the baby’s hemoglobin and bilirubin levels.
In patients with mild HDFN, a newborn may receive phototherapy for the treatment of neonatal jaundice. Exchange transfusions, which are administered after birth, may be used to treat fetal anemia and severe jaundice in neonates.
The use of intravenous immunoglobulin (IVIG) is recognized as a noninvasive way in which to prevent or delay the onset of severe anemia. IVIG is administered once weekly to pregnant women who are considered to be at elevated risk for development of early-onset HDFN. In fact, IVIG treatment can be initiated at the end of a woman’s first trimester and until birth.
Prior to administration of IVIG or other treatments, the fetal blood group should be assessed with the use of cell-free fetal DNA (cffDNA). Fetal middle cerebral artery-peak systolic blood flow velocity (MCA-PSV) ultrasound is another noninvasive method for the detection of possible fetal anemia.
Another treatment option involves maternal plasma exchange, in which alloantibodies are cleared from the mother’s circulation.
Accumulating evidence has shown that IVIG can be used “as part of an immunomodulatory package of care for women with severe HDFN.” In such situations, IVIG is used along with other treatments, in order to improve patient outcomes.
Specific immunomodulatory therapy with the monoclonal antibody nipocalimab is being recognized as a potential effective treatment for severe HDFN. Nipocalimab “selectively blocks the neonatal Fc receptor (FcRn) to reduce levels of circulating . . . IgG.”
