A woman attends the antenatal clinic with a history of exposure to rubella infection at a period of amenorrhea of 10 weeks. Her immune status is not known.What is the next step in the management?
**Core Concept**
Rubella infection during pregnancy, especially in the first trimester, can lead to congenital rubella syndrome (CRS), characterized by fetal anomalies, miscarriage, or stillbirth. The risk of CRS is highest if the mother is seronegative for rubella antibodies.
**Why the Correct Answer is Right**
If the woman's immune status is unknown, it is essential to determine her rubella immunity status. A rubella IgG antibody test will detect both naturally acquired and vaccine-induced immunity. If the test is negative, it indicates that the woman is not immune, and further management would involve vaccination with the measles, mumps, and rubella (MMR) vaccine, ideally before the 20th week of gestation. However, in the case of a known exposure at 10 weeks of gestation, immediate vaccination is not recommended due to theoretical concerns of transmission of the attenuated vaccine virus to the fetus.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because immediate vaccination with MMR is not recommended in the case of a known exposure to rubella during pregnancy.
**Option B:** This option is incorrect because a rubella IgM antibody test is used to detect acute infection, not to assess immunity status.
**Option C:** This option is incorrect because administration of immune globulin (antirubella immunoglobulin) is not recommended for individuals with unknown immunity status.
**Option D:** This option is incorrect because a rubella vaccination is not recommended in the case of a known exposure to rubella during pregnancy.
**Clinical Pearl / High-Yield Fact**
In cases of known or suspected rubella exposure during pregnancy, it is crucial to assess the woman's rubella immunity status before considering vaccination or immune globulin administration.
**Correct Answer: C. Obtain a rubella IgG antibody test to assess the woman's immunity status.**