Which test is used to assess rubella immunity in prenatal care?

• A. HIV
• B. RPR
• C. Rubella IgG
• D. hCG

Answer: (C)

Assessing rubella immunity during prenatal care is done by measuring rubella-specific IgG antibodies in the blood. A detectable IgG indicates prior exposure or vaccination and provides protective immunity against rubella during pregnancy. If the IgG is negative, the patient is not immune and remains at risk for rubella infection that could affect the fetus; vaccination with MMR is avoided during pregnancy and would be addressed after delivery. IgM antibodies would indicate an active or recent infection rather than immunity, so they’re not used for routine immunity screening. The other tests screen for HIV, syphilis, or pregnancy status, not rubella immunity, so they don’t substitute for the IgG rubella test.