From the Guidelines
A pregnant woman with indeterminate rubella immunity should not receive the rubella vaccine during pregnancy but should be vaccinated immediately after delivery. The MMR (measles, mumps, rubella) vaccine is a live attenuated vaccine that is contraindicated during pregnancy due to the theoretical risk of transmitting the virus to the developing fetus, which could potentially cause congenital rubella syndrome 1. Instead, these women should be counseled about avoiding exposure to rubella during pregnancy and should receive the MMR vaccine in the immediate postpartum period, ideally before discharge from the hospital. The standard adult dose is one 0.5 mL subcutaneous injection. Vaccination postpartum is safe even for breastfeeding mothers. This approach protects the woman during future pregnancies while avoiding any potential risk to the current pregnancy. During the current pregnancy, if the woman is exposed to rubella, she should be monitored closely with serologic testing to determine if infection has occurred, as rubella infection during pregnancy can cause serious birth defects.
Some key points to consider:
- The risk of vaccine-associated malformation is considered negligible, and rubella vaccination during pregnancy should not ordinarily be a reason to recommend interruption of pregnancy 1.
- Recent administration of immune globulins can inhibit the immune response to measles and rubella vaccine, but this does not affect the recommendation for postpartum vaccination 1.
- Previous administration of whole blood or other blood products containing antibody does not interfere with an immune response and is not a contraindication to postpartum vaccination 1.
- The postpartum vaccination of rubella-susceptible women with the rubella or MMR vaccine should not be delayed because anti-Rho(D) IG (human) or any other blood product was received during the last trimester of pregnancy or at delivery 1.
From the Research
Rubella Immunity and Pregnancy
- A patient found to be rubella immune indeterminant and newly pregnant should be managed according to the guidelines for rubella vaccination in pregnancy 2.
- The studies provided do not directly address the timing of rubella booster immunization for a pregnant woman with indeterminant immunity 3, 4, 5, 6.
- However, it is known that rubella infection during pregnancy can cause congenital rubella syndrome, and vaccination is an effective way to prevent this 2.
- The American College of Obstetricians and Gynecologists (ACOG) recommends that all pregnant women be screened for rubella immunity, and those who are nonimmune should be vaccinated postpartum 2.
- There is no specific guidance on when to administer a booster dose to a pregnant woman with indeterminant immunity, but it is generally recommended to avoid live vaccines, including the MMR vaccine, during pregnancy 2.
- The decision to administer a booster dose should be made on a case-by-case basis, taking into account the individual's risk factors and the potential benefits and risks of vaccination 4, 5.
- Further research is needed to determine the optimal timing and approach for rubella vaccination in pregnant women with indeterminant immunity 6.
Key Considerations
- Rubella immunity is typically assessed through measurement of IgG antibody titers, with a titer of ≥10 IU/mL considered indicative of immunity 3, 5.
- Pregnant women with indeterminant immunity may be at risk of rubella infection, which can have serious consequences for the fetus 2.
- Vaccination is an effective way to prevent rubella infection, but the timing and approach for vaccination in pregnant women with indeterminant immunity are not well established 4, 6.