Bacille Calmette-Guerin

BCG vaccine, used outside the United States for the prevention of tuberculosis, can theoretically cause disseminated disease and thus affect the fetus. Although no harmful effects to the fetus have been associated with BCG vaccine, its use is not recommended for U.S. travelers. Skin testing for tuberculosis exposure before and after travel is preferable when the risk is high.

Diphtheria-Tetanus Immunizations

The combination diphtheria-tetanus primary series immunization should be given if the pregnant traveler has not been immunized or is only partially immunized. Previously vaccinated pregnant women who have not received a Td vaccination within the previous 10 years should receive a booster dose. However, if they have not received one dose of Tdap as an adult, this preparation should be used instead of Td. Although no evidence suggests teratogenicity with tetanus or diphtheria toxoids or with the use of Tdap, the preference would be for either of their administration to occur during the second or third trimester.

Hepatitis A Immunizations

HAV is usually no more severe during pregnancy than at other times and does not affect the outcome of pregnancy. There have been reports, however, of acute fulminant disease in pregnant women during the third trimester, when there is also an increased risk of premature labor and fetal death. These events have occurred in women from developing countries and might have been related to underlying malnutrition. HAV is rarely transmitted to the fetus, but transmission can occur during viremia or from fecal contamination at delivery.

Immune Globulin Preparations Immunizations

No known fetal risk exists from passive immunization of pregnant women with immune globulin preparations. Administration of IG can be used pre-exposure as protection against hepatitis A or for postexposure management for other viral diseases if warranted.

Influenza Immunizations

Because of the increased risk for influenza-related complications, women who will be pregnant during the influenza season of their travel destination should be vaccinated with inactivated vaccine, when vaccine is available. Vaccine can be administered in any trimester and is especially recommended for those with chronic diseases and an increased risk of influenza-related complications. Data from influenza immunization with inactivated vaccine of more than 2,000 pregnant women have not demonstrated an association with adverse fetal effects. Live attenuated influenza vaccines (LAIV), such as certain nasal preparations, are contraindicated during pregnancy.

Japanese Encephalitis Immunizations

No information is available on the safety of Japanese encephalitis vaccine during pregnancy. It should not be routinely administered during pregnancy. Pregnant women who must travel to an area where the risk of JE is high should be vaccinated when the theoretical risks are outweighed by the risk of infection to the mother and developing fetus.

Measles, Mumps, and Rubella Immunizations

The measles vaccine, as well as the measles, mumps, and rubella (MMR) vaccines in combination, are live-virus vaccines and are contraindicated in pregnancy. However, the Vaccine in Pregnancy Registry recently documented that no evidence of congenital rubella syndrome occurred in the offspring of more than 200 women who received rubella vaccine three months before to three months after conception. Rubella-susceptible women who are pregnant should be counseled about the potential risk for congenital rubella syndrome and the importance of being vaccinated after they are no longer pregnant. Because of the increased incidence of measles in children in developing countries and because of measles' communicability and potential for causing serious consequences in adults, susceptible women should delay traveling until after delivery, when immunization can be given safely. If an unprotected (without a history of physician-diagnosed measles or without at least two doses of measles vaccine) pregnant woman has a documented exposure to measles, IG should be given within 6 days to prevent illness.

Meningococcal Meningitis Immunizations

The polyvalent meningococcal meningitis vaccine (MPSV4) can be administered during pregnancy if the woman is entering an area where the disease is epidemic. Studies of vaccination during pregnancy have not documented adverse effects among either pregnant women or neonates and have shown the vaccine to be efficacious. Based on data from studies involving the use of the polysaccharide meningococcal vaccines administered during pregnancy, altering meningococcal vaccination recommendations during pregnancy is unnecessary. The conjugate (MCV4) meninigococcal vaccine is safe and immunogenic among nonpregnant persons ages 11-55, but no data are available on the safety of MCV4 during pregnancy. Women of childbearing age who become aware that they were pregnant when they received MCV4 vaccination should contact their health-care provider or the vaccine manufacturer.

Pneumococcal (PPV23) Immunizations

The safety of pneumococcal polysaccharide vaccine during the first trimester of pregnancy has not been evaluated, although no adverse fetal consequences have been reported after inadvertent vaccination during pregnancy. Women with chronic diseases (such as asplenia or metabolic, renal, cardiac, or pulmonary diseases), smokers, and immunosuppressed women should consider vaccination.

Poliomyelitis Immunizations

There is no convincing evidence of adverse effects of inactivated poliovirus vaccine in pregnant women or developing fetuses. However, if not previously immunized, a pregnant woman traveling to an area where polio still occurs should be advised to have at least two doses of vaccine one month apart before departure, in accordance with the recommended schedules for adults. The pregnant traveler who is not protected against poliomyelitis has increased risks to both herself and her unborn fetus. Paralytic disease can occur with greater frequency when infection develops during pregnancy. Anoxic fetal damage has also been reported, with up to 50% mortality in neonatal infection.

Rabies Immunizations

Because of the potential consequences of inadequately treated rabies exposure and because there is no indication that fetal abnormalities have been associated with cell culture rabies vaccines, pregnancy is not considered a contraindication to rabies postexposure prophylaxis. If the risk of exposure to rabies is substantial, preexposure prophylaxis may also be indicated during pregnancy.