From the Guidelines
RhoGAM (Rho(D) immune globulin) should be administered as a 50 mg dose within 72 hours of spontaneous or induced abortion at less than 12 weeks of gestation, or a 300 mg dose if the lower dose is unavailable. This recommendation is based on the most recent guidelines from the Society for Maternal-Fetal Medicine, as reported in the American Journal of Obstetrics and Gynecology in 2024 1. The administration of RhoGAM is crucial to prevent the formation of antibodies against Rh-positive fetal red blood cells in Rh-negative women.
- Key considerations for RhoGAM administration include:
- Dose: 50 mg or 300 mg, depending on availability and clinical setting
- Timing: within 72 hours of spontaneous or induced abortion at less than 12 weeks of gestation
- Priority: postpartum patients and antenatal patients at later gestational ages should be prioritized for available doses when supply is limited
- Alternative products: equivalent RhIg products, such as HyperRHO S/D or Rhophylac, may be substituted if the typically used brand is not available 1. The goal of RhoGAM administration is to prevent hemolytic disease of the newborn in future pregnancies with Rh-positive fetuses, and to minimize the risk of resource over-utilization in clinical settings where access to the lower dose may be limited.
From the FDA Drug Label
Rho(D) Immune Globulin (Human) — HyperRHO® S/D Full Dose treated with solvent/detergent is a colorless to pale yellow or pink sterile solution of immune globulin containing antibodies to Rho(D) for intramuscular administration; it is preservative-free, in a latex-free delivery system. The administration of Rho(D) Immune Globulin (Human) is by intramuscular injection.
- The intramuscular route is the recommended method of administration for RhoGAM (Rho(D) immune globulin) 2, 2.
From the Research
Administration of RhoGAM
RhoGAM, also known as Rho(D) immune globulin, is administered to prevent Rh hemolytic disease of the fetus and newborn. The administration of RhoGAM can be done through two routes:
- Intramuscular (IM) injection
- Intravenous (IV) injection
Comparison of Administration Routes
Studies have compared the efficacy and effectiveness of IM and IV administration of anti-D IgG in preventing RhD alloimmunization in RhD-negative pregnant women. According to 3, both IM and IV administration of anti-D are equally effective, but the choice of route depends on available preparations, dose, and patient preferences.
Timing of Administration
RhoGAM is typically administered to RhD-negative mothers at 28 weeks of gestation and within 72 hours of potential maternal exposure to fetal red cells 3, 4, 5. It is also given shortly after delivery if the baby is RhD-positive.
Dose and Preparation
The dose of RhoGAM can vary, but a common dose is 1500 IU (300 microgram) 3. The preparation of RhoGAM can also vary, with different products available for IM or IV administration.
Special Considerations
In some cases, RhoGAM may not be necessary for women with certain RhD variants, such as molecularly defined Asian-type DEL (c.1227G>A) 6. Additionally, RhoGAM has been shown to have immunosuppressive properties and may be used to modulate antibody levels in situations other than classical suppression of anti-D production 7.