During an otherwise normal low-risk pregnancy, travel can be planned most safely between the 18th and 32nd weeks. Commercial flying in pressurized cabins does not pose a threat to the fetus. An aisle seat will allow frequent walks. Adequate fluids should be taken during the flight.

It is not advisable to travel to endemic areas of yellow fever in Africa or Latin America; similarly, it is inadvisable to travel to areas of Africa or Asia where chloroquine-resistant falciparum malaria is a hazard, since complications of malaria are more common in pregnancy.

Ideally, all immunizations should precede pregnancy. Live virus products are contraindicated (measles, rubella, yellow fever), including smallpox. Inactivated poliovaccine (Salk) can be used instead of the oral vaccine. Vaccines against pneumococcal pneumonia, meningococcal meningitis, and hepatitis A can be used as indicated. Influenza vaccine is indicated in all pregnant women who will be in their second or third trimester during “flu season.”

Pooled immune globulin to prevent hepatitis A is safe and does not carry a risk of HIV transmission. Hepatitis A vaccine contains formalin-inactivated virus but can be given in pregnancy when needed. Chloroquine can be used for malaria prophylaxis in pregnancy, and proguanil is also safe.

Water should be purified by boiling, since iodine purification may provide more iodine than is safe during pregnancy.

Do not use prophylactic antibiotics or bismuth subsalicylate during pregnancy to prevent diarrhea. Use oral rehydration fluids, and treat bacterial diarrhea with erythromycin or ampicillin if necessary.