What is rubella IgG antibody? It's on the standard blood tests panel for pregnancy.

Infection response. Rubella, or any, igg antibody, is your body's response to exposure to an infection, such as a bacteria or virus (antigen). A positive result means you have immunity and do not need a booster.
Evidence of immunity. Rubella is one of the worst infections to get while pregnant. It can trigger abortion, organ damage, hearing loss, blindness & heart defects in the fetus. A protective rubella IgG level means you either had it before or had the vaccine & your body is immune. When examined before a pregnancy they can give the vaccine if you are not immune. We avoid giving this vaccine during pregnancy.