Measles, mumps, and rubella are viral diseases that may adversely affect non-immune pregnant women and their fetuses/neonates. Prevention of these diseases and their complications can be achieved through measles-mumps-rubella (MMR) vaccination prior to pregnancy. The vaccine is contraindicated during pregnancy because it contains live, attenuated viruses that pose a theoretical risk to the fetus. However, accidental receipt of MMR vaccination is not known to cause maternal/fetal complications. MMR immunization is recommended to non-immune obstetric patients upon completion or termination of pregnancy.