Factors Affecting the Decision to Travel Before and During Pregnancy

Reproductive-aged women who may be planning both pregnancy and international travel should consider preconceptional immunization, when practical, to prevent disease in the offspring. Since as many as 50% of pregnancies are unplanned, reproductive-aged women should consider maintaining current immunizations during routine check-ups in case an unplanned pregnancy coincides with a need to travel. Preconceptional immunizations are preferred to vaccination during pregnancy, because they decrease risk to the unborn child. A woman should defer pregnancy for at least 28 days after receiving live vaccines (e.g., MMR, yellow fever), because of theoretical risk of transmission to the fetus (1). However, no harm to the fetus has been reported from the unintentional administration of these vaccines during pregnancy, and pregnancy termination is not recommended after an inadvertent exposure. Vaccination of susceptible women during the postpartum period, especially for rubella and varicella, is another opportunity for prevention, and these vaccines should be encouraged and administered (even for breastfeeding mothers) before discharge from the hospital (1).

According to the American College of Obstetrics and Gynecology, the safest time for a pregnant woman to travel is during the second trimester (18-24 weeks), when she usually feels best and is in least danger of spontaneous abortion or premature labor (2). A woman in the third trimester should be advised to stay within 300 miles of home because of concerns about access to medical care in case of problems such as hypertension, phlebitis, or premature labor. Pregnant women should be advised to consult with their health-care providers before making any travel decisions. Collaboration between travel health experts and obstetricians is helpful in weighing benefits and risks based on destination and recommended preventive and treatment measures. Table 9-2 lists relative contraindications to international travel during pregnancy (2,3). In general, pregnant women with serious underlying illnesses should be advised not to travel to developing countries.

TABLE 9-2. Potential contraindictions to international travel during pregnancy

Preparation for Travel During Pregnancy

Once a pregnant woman has decided to travel, a number of issues need to be considered before her departure.

• An intrauterine pregnancy should be confirmed by a clinician and ectopic pregnancy excluded before beginning any travel.
• Health insurance should provide coverage while abroad and during pregnancy. In addition, a supplemental travel insurance policy and a prepaid medical evacuation insurance policy should be obtained, although most may not cover pregnancy-related problems.
• Check medical facilities at the destination. For a woman in the last trimester, medical facilities should be able to manage complications of pregnancy, toxemia, and cesarean sections.
• Determine beforehand whether prenatal care will be required abroad and, if so, who will provide it. The pregnant traveler should also make sure prenatal visits requiring specific timing are not missed.
• Determine, before traveling, whether blood is screened for HIV and hepatitis B at the destination. The pregnant traveler should also be advised to know her blood type, and Rh-negative pregnant women should receive the anti-D immune globulin (a plasma-derived product) prophylactically at about 28 weeks’ gestation. The immune globulin dose should be repeated after delivery if the infant is Rh positive.

General Recommendations for Travel

A pregnant woman should be advised to travel with at least one companion; she should also be advised that, during her pregnancy, her level of comfort may be adversely affected by traveling. Typical problems of pregnant travelers are the same as those experienced by any pregnant woman: fatigue, heartburn, indigestion, constipation, vaginal discharge, leg cramps, increased frequency of urination, and hemorrhoids (3). During travel, pregnant women can take preventive measures including avoidance of gas-producing food or drinks before scheduled flights (entrapped gases can expand at higher altitudes) and periodic movement of the legs (to decrease venous stasis) (3). Pregnant women should always use seatbelts while seated, as air turbulence is not predictable and may cause significant trauma.

Signs and symptoms that indicate the need for immediate medical attention are vaginal bleeding, passing tissue or clots, abdominal pain or cramps, contractions, ruptured membranes, excessive leg swelling or pain, headaches, or visual problems.

Greatest Risks for Pregnant Travelers

Motor vehicle accidents are a major cause of morbidity and mortality for pregnant women. When available, safety belts should be fastened at the pelvic area. Lap and shoulder restraints are best; in most accidents, the fetus recovers quickly from the safety belt pressure. However, even after seemingly mild blunt trauma, a physician should be consulted.

Hepatitis E (see Chapter 4), which is not vaccine preventable, can be especially dangerous for pregnant women, for whom the case-fatality rate is 17%-33%. Therefore, pregnant women should be advised that the best preventive measures are to avoid potentially contaminated water and food, as with other enteric infections.

Scuba diving should be avoided in pregnancy because of the risk of decompression syndrome in the fetus.

TABLE 9-3. Half-lives of selected antimalarial drugs

Specific Recommendations for Pregnancy

Air Travel During Pregnancy

Commercial air travel poses no special risks to a healthy pregnant woman or her fetus. The American College of Obstetricians and Gynecologists (ACOG) states that women with healthy, single pregnancies can fly safely up to 36 weeks’ gestation (2). The lowered cabin pressures (kept at the equivalent of 1,524-2,438 meters [5,000-8,000 feet]) affect fetal oxygenation minimally because of the favorable fetal hemoglobin-oxygen dynamics. If required for some medical indications, supplemental oxygen should be arranged in advance (see Chapter 7). Severe anemia, sickle-cell disease or trait, or history of thrombophlebitis are relative contraindications to flying. Pregnant women with placental abnormalities or risks for premature labor should avoid air travel (2). Each airline has policies regarding pregnancy and flying; it is always safest to check with the airline when booking reservations, because some will require medical forms to be completed. Domestic travel is usually permitted until the pregnant traveler is in week 36 of gestation, and international travel may be permitted until weeks 32-35, depending on the airline (2,3). A pregnant woman should be advised always to carry documentation stating the expected day of delivery.

Airport security radiation exposure is minimal for pregnant women and has not been linked to an increase in adverse outcomes for unborn children to date (4). However, because of early reports of a possible association of radiation exposure during pregnancy and subsequent increased risk of childhood leukemia and cancer (5), a pregnant passenger may request a hand or wand search rather than being exposed to the radiation of the airport security machines.

An aisle seat at the bulkhead will provide the most space and comfort, but a seat over the wing in the midplane region will give the smoothest ride. A pregnant woman should be advised to walk every half hour during a smooth flight and flex and extend her ankles frequently to prevent phlebitis. The safety belt should always be fastened at the pelvic level. Dehydration can lead to decreased placental blood flow and hemoconcentration, increasing risk of thrombosis. Thus, pregnant women should drink plenty of fluids during flights.

For pregnant flight attendants and pilots, working air travel is restricted by most airlines by 20 weeks gestation (2).

Travel to High Altitudes During Pregnancy

Acclimatization responses at altitude act to preserve fetal oxygen supply, but all pregnant women should avoid altitudes higher than 3,658 meters (12,000 feet). In addition, altitudes higher than 2,500 meters (8,200 feet) should be avoided in late or high-risk pregnancy. Pregnant women who must travel to high altitude should postpone exercise until acclimatized.

Food- and Waterborne Illness During Pregnancy

It is especially important for pregnant women to adhere strictly to food and water precautions in developing countries because the consequences may be more severe than diarrhea and may have serious sequelae (e.g., toxoplasmosis, listeriosis) (see Chapter 4).

Suspect drinking water should be boiled to avoid long-term use of iodine-containing purification systems. Iodine tablets can probably be used for travel up to several weeks, but congenital goiters have been reported in association with administration of iodine-containing drugs during pregnancy. Oral rehydration is the mainstay of therapy for travelers’ diarrhea. Bismuth subsalicylate compounds are contraindicated because of the theoretical risks of fetal bleeding from salicylates and teratogenicity from the bismuth. The combination of kaolin and pectin may be used, and loperamide should be used only when necessary. The antibiotic treatment of travelers’ diarrhea during pregnancy can be complicated. Azithromycin or an oral third-generation cephalosporin may be the best options for treatment if an antibiotic is needed.

Malaria During Pregnancy

Malaria in pregnancy carries significant morbidity and mortality for both the mother and the fetus. Pregnant women should be advised to avoid travel to malaria-endemic areas if possible. Women who do choose to go to malarious areas can reduce their risk of acquiring malaria by following several preventive approaches (see Chapter 4). Because no preventive method is 100% effective, they should seek care promptly if symptoms of malaria develop. Pregnant women traveling to malarious areas should 1) remain indoors between dusk and dawn, if mosquitoes are active outdoors during this time; 2) if outdoors at night, wear light-colored clothing, long sleeves, long pants, and shoes and socks; 3) stay in well-constructed housing with air-conditioning and/or screens; 4) use permethrin-impregnated bed nets; and 5) use insect repellents containing DEET as recommended for adults, sparingly, but as needed (see Chapter 2). Pyrethrum-containing house sprays may also be used indoors if insects are a problem. If possible, remaining in cities or areas of cities that are at low (or lower) risk for malaria can help reduce the chances of infection. Pregnant travelers should be under the care of providers knowledgeable in the care of pregnant women in tropical areas (6).

For pregnant women who travel to areas with chloroquine-sensitive Plasmodium falciparum malaria, chloroquine has been used for malaria chemoprophylaxis for decades with no documented increase in birth defects. For pregnant women who travel to areas with chloroquine-resistant P. falciparum, mefloquine should be recommended for chemoprophylaxis during the second and third trimesters (6). For women in their first trimester, most evidence suggests that mefloquine prophylaxis causes no significant increase in spontaneous abortions or congenital malformations if taken during this period (6) (see Chapter 4).

Because there is no evidence that chloroquine and mefloquine are associated with congenital defects when used for prophylaxis, CDC does not recommend that women planning pregnancy need to wait a specific period of time after their use before becoming pregnant (6). However, if women or their health-care providers wish to decrease the amount of antimalarial drug in the body before conception, Table 9-3 provides information on the half-lives of selected antimalarial drugs. After two, four, and six half-lives, approximately 25%, 6%, and 2% of the drug remain in the body.

Doxycycline and primaquine are contraindicated for malaria prophylaxis during pregnancy, because both may cause adverse effects on the fetus (6).

Malaria must be treated as a medical emergency in any pregnant traveler. A woman who has traveled to an area that has chloroquine-resistant strains of P. falciparum should be treated as if she as illness caused by chloroquine-resistant organisms. Because of the serious nature of malaria, quinine or intravenous quinidine should be initiated, and the case should be managed in consultation with an infectious disease or tropical medicine specialist. The management of malaria in a pregnant woman should include frequent blood glucose determinations and careful fluid monitoring: these requirements may necessitate intensive care supervision.

Immunizations

Risk to a developing fetus from vaccination of the mother during pregnancy is primarily theoretical. No evidence exists of risk from vaccinating pregnant women with inactivated virus or bacterial vaccines or toxoids (7). The benefits of vaccinating pregnant women usually outweigh potential risks when the likelihood of disease exposure is high, when infection would pose a risk to the mother or fetus, and when the vaccine is unlikely to cause harm (Table 9-4).

The following information is intended for women who may require immunizations during pregnancy. Pregnant travelers may visit areas of the world where diseases eliminated by routine vaccination in the United States are still endemic and therefore may require immunizations before travel.

Bacille Calmette-Guérin (BCG)

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 (+/- Pertussis)

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

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.

Hepatitis B

The hepatitis B vaccine may be administered during pregnancy and is recommended for pregnant women at risk for hepatitis B virus infection.

Immune Globulin Preparations

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 dis-eases if warranted.

Influenza

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 (8). 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

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

The measles vaccine, as well as the measles, mumps, and rubella (MMR) vaccines in combination, are live-virus vaccines and are contraindicated in pregnancy (9,10). 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 3 months before to 3 months after conception (9). 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

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 (11). 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)

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

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

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 (12).

Typhoid

No data are available on the use of either typhoid vaccine in pregnancy. The Vi capsular polysaccharide vaccine (ViCPS) injectable preparation is the vaccine of choice during pregnancy because it is inactivated and requires only one injection. The oral Ty21a typhoid vaccine is not absolutely contraindicated during pregnancy, but it is live attenuated and thus has theoretical risk (13).

Varicella

Women who are pregnant or planning to become pregnant should not receive the varicella vaccine (14). Nonimmune pregnant women should consider postponing travel until after delivery when the vaccine can be given safely. Varicella zoster immune globulin (VZIG) should be strongly considered within 96 hours of exposure for susceptible, pregnant women who have been exposed. However, VZIG may not be readily available (14).

Yellow Fever

The safety of yellow fever vaccination during pregnancy has not been established, and the vaccine should be administered to a pregnant woman only if travel to an endemic area is unavoidable and if an increased risk for exposure exists. In these instances, the vaccine should be administered, and infants born to these women should be monitored closely for evidence of congenital infection and other possible adverse effects resulting from yellow fever vaccination. Further, serologic testing to document an immune response to the vaccine can be considered, because the seroconversion rate for pregnant women may be lower than in other healthy adults (15).

If traveling to or transiting regions within a country where the disease is not a current threat but where policy requires a yellow fever vaccination certificate, pregnant travelers should be advised to carry a physician’s waiver, along with documentation (of the waiver) on the immunization record.

TABLE 9-4. Vaccination during pregnancy

The Travel Health Kit During Pregnancy

Additions and substitutions to the usual travel health kit (see Chapter 2) need to be made during pregnancy. Talcum powder, a thermometer, oral rehydration salt packets, prenatal vitamins, an antifungal agent for vaginal yeast, acetaminophen, and a sunscreen with a high SPF should be carried. Women in the third trimester may be advised to carry a blood-pressure cuff and urine dipsticks so they can check for proteinuria and glucosuria, both of which would require prompt medical attention. Antimalarial and antidiarrheal self-treatment medications should be evaluated individually, depending on the traveler’s itinerary and her health history. Most medications should be avoided, if possible.

References

1. American College of Obstetricians and Gynecologists. ACOG Committee Opinion No. 282. Immunization during pregnancy. Obstet Gynecol. 2003;101:207-12.
2. American College of Obstetricians and Gynecologists. ACOG Committee Opinion No. 264. Air travel during pregnancy. Obstet Gynecol. 2001;98:1187-8.
3. Bia FJ. Medical considerations for the pregnant traveler. Infect Dis Clin North Am. 1992;6:371-88.
4. Barish RJ. In-flight radiation exposure during pregnancy. Obstet Gynecol. 2004;103:1326-30.
5. Boice JD Jr., Miller RW. Childhood and adult cancer after intrauterine exposure to ionizing radiation. Teratology. 1999;59:227-33.
6. CDC. Preventing malaria in travelers. http://www.cdc.gov/malaria/pdf/travelers.pdf. (Accessed 6/6/2006.)
7. CDC. Guidelines for vaccinating pregnant women. Recommendations of the Advisory Committee on Immunization Practices (ACIP). October 1998; Updated September 2006. http://www.cdc.gov/nip/publications/preg_guide.htm. (Accessed 18 November 2006)
8. CDC. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2005;54(No. RR-8):11.
9. CDC. Notice to Readers: Revised ACIP recommendation for avoiding pregnancy after receiving a rubella-containing vaccine. MMWR Recomm Rep. 2001;50(No. 49);1117.
10. CDC. Measles, mumps, and rubella—vaccine use and strategies for elimination of measles, rubella, and congenital rubella syndrome and control of mumps: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 1998; 47(No. RR-8):32-3.
11. CDC. Prevention and control of meningococcal disease: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2005;54(No. RR-7):15.
12. CDC. Human rabies prevention—United States, 1999: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 1999;48(No. RR-1):17.
13. CDC. Typhoid immunization: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 1994;43(No. RR-14):7.
14. CDC. Prevention of varicella: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 1996;45(No. RR-11):19.
15. CDC. Yellow fever vaccine: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2002. MMWR Recomm Rep. 2002;51(No. RR-17):7.

MADELINE SUTTON