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 bacterial vaccine
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. Children under 2 or those who spend time in groups of children can be at higher risk of catching pneumococcal disease. Pneumococcal disease can cause serious illnesses such as pneumonia and meningitis. A review looking at the pneumococcal vaccine in pregnancy found that there was not enough research to say that this vaccination reduced the number of babies developing pneumococcal disease. Pregnant women, babies and infants are at risk of serious problems from the influenza virus. A review into haemophilus influenza type B and viral influenza found one good piece of research that showed the flu vaccine reduced the number of women and babies who caught flu. Hib can cause bacterial meningitis and pneumonia. There was not enough research found in the review to show whether giving the Hib vaccine reduced the number of mothers and babies with Hib. More research is needed. Hepatitis B is a liver infection which can be passed from mother to baby at birth and can often be passed to children under 5 from other infected children. Healthy adults who catch Hep B often recover but babies and children are much more likely to develop chronic Hep B. Chronic Hep B can result in liver cancer. It is much more common in low income countries. It has been suggested that vaccinating mothers against Hep B in pregnancy may reduce the risk of the baby becoming infected. At the moment, there is not enough research to show that the Hep B vaccination is safe in pregnancy. More research is needed. Data regarding anthrax vaccination during pregnancy are very limited but show no confirmed effect on the fetus.
Toxoids
s appear safe during pregnancy and are administered in many countries of the world to prevent neonatal tetanus. The World Health Organization states more than 180,000 newborns die and over 30,000 women die each year from tetanus. Neonatal tetanus is usually passed to the baby via unsterile instruments being used to cut the umbilical cord or other unclean practices at delivery. The tetanus vaccine has shown to be successful in preventing babies from developing tetanus and deaths from tetanus. It is recommended by the American Congress of Obstetrics and Gynecologists the following schedule for pregnant women to receive the vaccine--
Schedule if never immunized: three doses in 0, 4, and 6–12 months
Schedule if unknown immunization: at least two doses** in the late second or third trimester. The National Business Group on Health states an analysis of pregnant women who received at least two doses had 98% effectiveness of the tetanus vaccine.
Not administered in pregnancy: a dose in postpartum period
*One of the doses during pregnancy should be the Tdap**.
References: American College of Obstetricians and Gynecologists, Committee Opinion. Update on immunization and pregnancy: tetanus, diphtheria, and pertussis vaccination. 521, 690–1. Retrieved from http://www.acog.org/Resources_And_Publications/Committee_Opinions/Committee_on_ Obstetric_Practice/Update_on_Immunization_and_Pregnancy_Tetanus_Diphtheria_and_ Pertussis_Vaccination National Business Group on Health.. Tetanusfor Pregnant Women. Retrieved from http://www.businessgrouphealth.org/preventive/topics/tetanus.cfm#9 Department of Making Pregnancy Safer, World Health Organization., Standards of Maternal and Neonatal Care. Retrieved from http://whqlibdoc.who.int/hq/2007/a91272.pdf
Immune globulins
Immune globulins are used for post exposure prophylaxis 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.
