Infections such as measles, rubella, and toxoplasmosis can cause serious health problems in the baby if contracted during early pregnancy. Measles and rubella antibody tests indicate whether you have immunity against these diseases. If you do not have immunity (i.e., you are susceptible), your doctor may recommend vaccination before pregnancy. Since the measles-rubella vaccine contains attenuated live viruses, it is important to avoid pregnancy for three months after vaccination and to check your immunity status at the end of this period.