Immunization during pregnancy

Immunization during pregnancy, that is the administration of a vaccine to a pregnant woman, is not a routine event as it is generally preferred to administer vaccines either prior to conception or in the postpartum period. When widespread vaccination is used, the risk for an unvaccinated pregnant patient to be exposed to a related infection is low, allowing for postponement, in general, of routine vaccinations to the postpartum period. Nevertheless, immunization during pregnancy may occur either inadvertently, or be indicated in a special situation, when it appears prudent to reduce the risk of a specific disease for a potentially exposed pregnant woman or her fetus.

As a rule of thumb the vaccination with live virus or bacteria is contraindicated in pregnancy.

Live attenuated virus vaccine

In general, the administration of live attenuated virus vaccines are contraindicated during pregnancy, this includes vaccines against measles, mumps, poliomyelitis, rubella, yellow fever, and varicella. It should be noted, that cases of fetal damage due to the inadvertent administration of these vaccines has not been confirmed. Also, no case of congenital rubella syndrome has been reported when rubella vaccine was given inadvertently during a pregnancy. MMR vaccination can be given during lactation and does not affect the baby.

The CDC recommends that non-pregnant women who receive the MMR vaccine or varicella vaccination should wait four weeks before getting pregnant.

Inactivated or assembled virus vaccine

In situations where inactivated virus or parts of a virus are administered, in general, there is no contraindication to immunization during pregnancy. Thus influenza vaccination is given to pregnant women at risk, as are vaccinations against hepatitis A and B. In the case of rabies vaccination, information is very limited.

HPV vaccine was introduced in 2006. It is not to be used during pregnancy. It is a pregnancy category B agent and no adverse effects upon the fetus have been reported with inadvertent use, however, the experience is limited and accidental administration during pregnancy needs to be reported to the pregnancy registry of the manufacturer or the CDC.

Live attenuated bacterial vaccine

BCG vaccine is used against tuberculosis and is contraindicated in pregnancy.

Inactivated bacterial vaccine

Inactivated bacterial vaccine is used during pregnancy for women who have a specific risk of exposure and disease. Vaccination against pneumococcus or meningococcus infections, or typhoid fever show no confirmed side effects regarding the fetus, however data are limited. Data regarding anthrax vaccination during pregnancy are very limited but show no confirmed effect on the fetus.

Toxoids

Tetanus toxoids appear safe during pregnancy.

Immune globulins

Immune globulins are used for post exposure prophyllaxis and not associated with reports that harm is done to the fetus. Such agents are considered in pregnant women exposed to hepatitis B, rabies, tetanus, varicella, and hepatitis A.

Up-to-date information about vaccination and pregnancy can be obtained from the CDC. [http://www.cdc.gov/nip]

References

# ACOG Committee Opinion, Number 282, January 2003 (Obstet Gynecol 2003;101:207-12)
# [http://www.cdc.gov/nip/home-hcp.htm CDC information]