This test is used to measure the levels of IgM antibodies against Rubella virus, the causative agent of German measles. Rubella infection during early pregnancy can pose significant risks to the developing fetus, potentially leading to severe complications such as heart defects, growth retardation, hearing loss, vision problems, blood disorders, and pneumonia. If contracted during childhood, rubella can also lead to long-term health issues like central nervous system disorders, immune system problems, and thyroid conditions. Testing for Rubella IgM antibodies helps identify recent or active infection, particularly important in pregnant women to assess potential risks to the fetus.