Vaccines are an important part of pregnancy and prenatal care. However, there are some vaccines which contain live viruses and therefore can not be given in pregnancy. These include the rubella and varicella (chicken pox) vaccine. It is recommended that women check their immunity against these viruses prior to pregnancy through a simple blood test. If you are found to be non-immune, you could experience dangerous consequences to your health and/or the health of your baby if you became infected in pregnancy. Updating these vaccines 6 months prior to a pregnancy is reasonable to consider to optimize your health.