II. Indications
- Prevention of Rh Sensitization in Rh Negative mother (risk of Hemolytic Disease of the Newborn)
III. Contraindications
- Rh Positive patients
- Rh Sensitized patients
IV. Mechanism
- Immunoglobulin Extracted from pooled human serum given to Rh Negative pregnant women
- Prevents maternal Antibody response to a fetus with Rh Positive RBCs, resulting in Rh Sensitization
- RHO Immune Globulin binds Rho Antigens that have crossed into maternal circulation
- Immunoglobulin binding of Rho Antigens masks them from maternal immune response
V. Dosing
- Timing
- Uterine bleeding or Trauma
- Routine scheduled dosing for Rh Negative mother
- Gestational Age: 28 weeks
- Postpartum within 72 hours of delivery
-
Uterine Bleeding in Pregnancy
- RhoGAM dose based on Kleihauer-Betke
- Give 300 mcg IM per 30 ml fetal whole blood or 15 ml pRBC
- No Uterine bleeding (routinely timed administration)
- Gestation under 13 weeks: RhoGAM 50 mcg IM
- Gestation over 13 weeks: RhoGAM 300 mcg IM
- Updates on times when RhoGAM (and Rh testing) are not required (2024 ACOG updates)
- RhoGAM is NOT required for Miscarriage or abortion <12 weeks gestation
- However, RhoGAM is still recommended in Ectopic Pregnancy <12 weeks or when dates are uncertain
- (2024) Obstet Gynecol 144(6):e140-3 +PMID: 39255498 [PubMed]
VI. Adverse Effects
- Hypersensitivity Reactions (including Anaphylaxis)
- Hemolysis (if given to an Rh Positive patient)
- Bloodborne Communicable Disease
- As with all donor Blood Products, carefully screened in U.S. and exceedingly low risk
- Potential risk of Creutzfeldt Jakob Disease (or its variant)
- Injection site reaction
- Local swelling, warmth, induration, redness or mild pain
- Other less common effects
- Skin rash
- Myalgias
- Low grade fever
VII. Resources
- RHO Immune Globulin - RhoGAM (DailyMed)