From the Guidelines
RhoGAM is recommended to be administered within 72 hours of bleeding at 7 weeks gestation, with a 50 mg dose being adequate to cover the volume of potential feto-maternal hemorrhage in the first trimester. According to the Society for Maternal-Fetal Medicine statement published in the American Journal of Obstetrics and Gynecology in 2024 1, RhIg administration is indicated in such cases to prevent maternal sensitization to Rh-positive fetal blood. The recommended dose is 50 mg within 72 hours of the spontaneous or induced abortion, which is sufficient to cover the small volume of potential feto-maternal hemorrhage in the first trimester.
- Key points to consider:
- A 50 mg dose of RhIg is adequate for the first trimester
- Administration should occur within 72 hours of bleeding
- If the 50 mg dose is unavailable, a 300 mg dose may be used
- The choice of RhIg product may depend on availability, with equivalent products such as HyperRHO S/D or Rhophylac being acceptable substitutes 1.
- It is essential to consult with a healthcare provider to assess the specific situation and determine the best course of action, as the decision to administer RhoGAM may depend on various clinical factors, including the severity of bleeding and the patient's individual risk factors.
From the FDA Drug Label
Following threatened abortion at any stage of gestation with continuation of pregnancy, it is recommended that a full dose of HyperRHO S/D Full Dose (1500 IU; 300 mcg) be given. If pregnancy is terminated prior to 13 weeks’ gestation, where licensed, a single dose of HyperRHO® S/D Mini-Dose (250 IU; 50mcg) may be used instead of HyperRHO S/D Full Dose (1500 IU; 300 mcg)
Administration of Rhogam at 7 weeks with bleeding:
- If the pregnancy is continuing and there is bleeding at 7 weeks, a full dose of HyperRHO S/D Full Dose (1500 IU; 300 mcg) is recommended.
- However, if the pregnancy is terminated prior to 13 weeks, a single dose of HyperRHO® S/D Mini-Dose (250 IU; 50mcg) may be used instead of HyperRHO S/D Full Dose. 2
From the Research
Administration of Rhogam at 7 Weeks with Bleeding
- The study 3 suggests that there is minimal evidence to support the use of Rh immune globulin for first trimester spontaneous abortions to prevent maternal sensitization or development of hemolytic disease of the newborn.
- According to 4, forgoing Rh immunoglobulin administration before 12 weeks gestation is highly unlikely to increase the risk of Rh (D) antibody development.
- The study 5 recommends that after miscarriage or threatened abortion or induced abortion during the first 12 weeks of gestation, nonsensitized D-negative women should be given a minimum anti-D of 120 microg.
- However, the study 3 states that there is a paucity of well-designed research that examines maternal sensitization or hemolytic disease of the newborn as an outcome in patients receiving, versus not receiving, Rh immune globulin in first trimester bleeding.
- It is essential to consider the guidelines and recommendations from professional societies, such as the American College of Obstetricians & Gynecologists (ACOG), which may provide more specific guidance on the administration of Rhogam at 7 weeks with bleeding 6.
Considerations for Rhogam Administration
- The decision to administer Rhogam should be based on the individual patient's risk factors and medical history, as well as the current guidelines and recommendations from professional societies.
- The use of cell-free DNA tests to determine fetal Rh(D) status may be a reasonable approach to prioritize RhIg administration when supply is limited 6.
- The study 7 suggests that targeted antenatal anti-RhD prophylaxis, using cell-free fetal DNA in the maternal blood, may be a cost-effective approach to prevent RhD alloimmunization.
- However, the study 4 indicates that fetal RBC exposure during aspiration abortion <12 weeks gestation is below the calculated threshold to cause maternal Rh sensitization.