Women experience physiologic changes in pregnancy that require special consideration when traveling. With careful preparation, however, most pregnant women are able to travel safely.
The pretravel evaluation of a pregnant traveler (Box 7-1) should begin with a careful medical and obstetric history, with particular attention paid to gestational age and evaluation for high-risk conditions. A visit with an obstetrician should be a part of the pretravel assessment, to ensure routine prenatal care as well as identify any potential problems. The traveler should be provided with a copy of her prenatal records and physician’s contact information. Checking for immunity to various infectious diseases may obviate the need for some vaccines.
A review of the pregnant woman’s travel itinerary, including destinations, accommodations, and activities, should guide pretravel health advice. Preparation includes educating the pregnant woman regarding avoidance of travel-associated risks, the management of minor pregnancy discomforts, and recognition of more serious complications. Bleeding, severe pelvic or abdominal pain, contractions or premature labor, premature rupture of the membranes, symptoms of preeclampsia (unusual swelling, severe headaches, nausea and vomiting, vision changes), severe vomiting, diarrhea, dehydration, and symptoms of deep vein thrombosis (unusual swelling of leg with pain in calf or thigh) or pulmonary embolism (unusual shortness of breath) require urgent medical attention.
Pregnant travelers should pack a health kit that includes items such as prescription medications, hemorrhoid cream, antiemetic drugs, antacids, prenatal vitamins, medication for vaginitis or yeast infection, and support hose, in addition to the items recommended for all travelers (see Chapter 6, Travel Health Kits). Pregnant travelers should consider packing a blood pressure monitor if travel may limit access to a health center with blood pressure monitoring available.
Although travel is rarely contraindicated during a normal pregnancy, complicated pregnancies require extra consideration and may warrant a recommendation that travel be delayed (Box 7-2). Pregnant travelers should be advised that the risk of obstetric complications is highest in the first and third trimesters.
Obstetric emergencies are often sudden and life-threatening. Travel to areas where obstetric care may be less than the standard at home is inadvisable. For women traveling in the third trimester of pregnancy, it is recommended to identify international medical facilities capable of managing complications of pregnancy, delivery, a cesarean section, and neonatal problems.
Many health insurance policies do not cover complications of pregnancy or the newborn overseas. Supplemental travel health insurance should be strongly considered to cover pregnancy-related problems and care of the neonate, as needed. Evacuation insurance that includes coverage of pregnancy-related complications is also highly encouraged.
Pregnant women should be advised to wear seat belts, when available, on all forms of transport, including airplanes, cars, and buses. A diagonal shoulder strap with a lap belt provides the best protection. The shoulder belt should be worn between the breasts with the lap belt low across the upper thighs. When only a lap belt is available, it should be worn low, between the abdomen and the pelvis.
Most commercial airlines allow pregnant travelers to fly until 36 weeks’ gestation. Some limit international travel earlier in pregnancy, and some require documentation of gestational age. Pregnant travelers should check with the airline for specific requirements or guidance. Cabins of most commercial jetliners are pressurized to 6,000–8,000 ft (1,829–2,438 m) above sea level; the lower oxygen tension should not cause fetal problems in a normal pregnancy, but women with preexisting cardiovascular problems, sickle cell disease, or severe anemia (hemoglobin <8.0 g/dL) may experience the effects of low arterial oxygen saturation. Risks of air travel include potential exposure to communicable diseases, immobility, and the common discomforts of flying. Abdominal distention and pedal edema frequently occur. The pregnant traveler may benefit from an upgrade in airline seating and should seek convenient and practical accommodations (such as close proximity to the toilet) and aisle seating so she can move about frequently. Loose clothing and comfortable shoes are recommended.
Some experts report that the risk of deep vein thrombosis in pregnancy is 5–10 times higher than for nonpregnant women. Preventive measures include frequent stretching, walking and isometric leg exercises, and wearing graduated compression stockings (see Chapter 8, Deep Vein Thrombosis & Pulmonary Embolism).
Cosmic radiation during air travel poses little threat, but may be a consideration for pregnant travelers who are frequent fliers (such as aircrew). Older airport security machines are magnetometers and are not harmful to the fetus. Newer security machines use backscatter x-ray scanners, which emit low levels of radiation. Most experts agree that the risk of complications from radiation exposure from these scanners is extremely low.
Most cruise lines restrict travel beyond 28 weeks of pregnancy, and some as early as 24 weeks. Pregnant travelers may be required to carry a physician’s note stating that they are fit to travel, including the estimated date of delivery. Pregnant women should check with the cruise line for specific requirements or guidance. The pregnant traveler planning a cruise should be advised regarding motion sickness, gastrointestinal and respiratory infections, and the risk of falls on a moving vessel.
Air pollution may cause more health problems during pregnancy, as ciliary clearance of the bronchial tree is slowed and mucus more abundant. Body temperature regulation is not as efficient during pregnancy, and temperature extremes can cause more stress on the gravid woman. In addition, an increase in core temperature, such as with heat prostration or heat stroke, may harm the fetus. The vasodilatory effect of a hot environment might also cause fainting. For these reasons, accommodation should be sought in air-conditioned quarters and activities restricted in hot environments.
Pregnant women should avoid activities at high altitude unless trained for and accustomed to such activities; women unaccustomed to high altitudes may experience exaggerated breathlessness and palpitations. The common symptoms of acute mountain sickness (insomnia, headache, and nausea) are frequently also associated with pregnancy, and it may be difficult to distinguish the cause of the symptoms. Most experts recommend a slower ascent with adequate time for acclimatization. No studies or case reports show harm to a fetus if the mother travels briefly to high altitudes during pregnancy. However, it may be prudent to recommend that pregnant women not sleep at altitudes >12,000 ft (3,658 m), if possible. Probably the largest concern regarding high-altitude travel in pregnancy is that many such destinations are inaccessible and far from medical care (see Chapter 3, High-Altitude Travel & Altitude Sickness).
Pregnant travelers should be discouraged from undertaking unaccustomed vigorous activity. Swimming and snorkeling during pregnancy are generally safe, but waterskiing has resulted in falls that inject water into the birth canal. Most experts advise against scuba diving for pregnant women because of risk of fetal gas embolism during decompression. Riding bicycles, motorcycles, or animals presents risk of trauma to the abdomen.
Respiratory and urinary infections and vaginitis are more likely to occur and to be more severe in pregnancy. Pregnant women who develop travelers’ diarrhea or other gastrointestinal infections may be more vulnerable to dehydration than nonpregnant travelers. Strict hand hygiene and food and water precautions should be stressed (see Chapter 2, Food & Water Precautions). Bottled or boiled water is preferable to chemically treated or filtered water. Iodine-containing compounds should not be used to purify water for pregnant women because of potential effects on the fetal thyroid (see Chapter 2, Water Disinfection for Travelers). The treatment of choice for travelers’ diarrhea is prompt and vigorous oral hydration; however, azithromycin may be given to pregnant women if clinically indicated. Use of bismuth subsalicylate is contraindicated because it is associated with intrauterine growth problems and premature fetal ductus arteriosus.
Hepatitis A and E are both spread by the fecal-oral route. Hepatitis A has been reported to increase the risk of placental abruption and premature delivery. Hepatitis E is more likely to cause severe disease during pregnancy and may result in a case-fatality ratio of 15%–30%; when acquired during the third trimester, it is also associated with fetal complications and fetal death. Some foodborne illnesses of particular concern during pregnancy include toxoplasmosis and listeriosis; the risk during pregnancy is that the infection will cross the placenta and cause spontaneous abortion, stillbirth, or congenital or neonatal infection. The pregnant traveler should be warned, therefore, to avoid unpasteurized cheeses and undercooked meat products. Risk of fetal infection increases with gestational age, but severity of infection is decreased.
Parasitic diseases are less common but may cause concern, particularly in women who are visiting friends and relatives in developing areas. In general, intestinal helminths rarely cause enough illness to warrant treatment during pregnancy. Most, in fact, can safely be addressed with symptomatic treatment until the pregnancy is over. On the other hand, protozoan intestinal infections, such as Giardia, Entamoeba histolytica , and Cryptosporidium , often do require treatment. These parasites may cause acute gastroenteritis, severe dehydration, chronic malabsorption resulting in fetal growth restriction, and in the case of E. histolytica , invasive disease, including amebic liver abscess and colitis. Pregnant women should avoid swimming or wading in freshwater lakes, streams, and rivers that may harbor schistosomes.
Pregnant women should avoid mosquito bites when traveling in areas where vectorborne diseases are endemic. Preventive measures include use of bed nets, insect repellents, and protective clothing (see Chapter 3, Mosquitoes, Ticks & Other Arthropods). A more recent concern for pregnant women is Zika virus infection. Zika virus is spread primarily through the bite of an infected Aedes mosquito (Ae. aegypti and Ae. albopictus ) but can also be sexually transmitted. The illness associated with Zika may be asymptomatic or mild; however, some patients report acute onset of fever, rash, joint pain, and conjunctivitis that last for several days to a week after infection. Birth defects that can be caused by Zika infection during pregnancy include microcephaly and brain abnormalities. Because of the risk of birth defects, CDC recommends pregnant women not travel to areas where Zika is a risk, and take precautions to avoid sexual transmission of the virus. If travel cannot be avoided, pregnant women should strictly follow steps to prevent mosquito bites. Additional information, including the most current list of countries and territories where Zika virus is a risk, is available at www.cdc.gov/travel. Guidance for pregnant women can be found at the CDC Zika website (www.cdc.gov/pregnancy/zika/index.html).
Various systems are used to classify drugs with regard to their safety in pregnancy. In most cases, it is preferable to refer to specific data regarding the effects of a given drug during pregnancy rather than simply to depend on a classification.
Analgesics that can be used during pregnancy include acetaminophen and some narcotics. Aspirin may increase the incidence of abruption, and other anti-inflammatory agents can cause premature closure of the ductus arteriosus. Constipation may require a mild bulk laxative. Several simple remedies are often effective in relieving the symptoms of morning sickness. Nonprescription remedies include ginger, which is available as a powder that can be mixed with food or drinks such as tea. It is also available in candy, such as lollipops. Similarly, pyridoxine (vitamin B6) is effective in reducing symptoms of morning sickness and is available in tablet form, as well as lozenges and lollipops. Antihistamines such as meclizine and dimenhydrinate are often used in pregnancy for morning sickness and motion sickness and appear to have a good safety record.
In the best possible scenario, a woman should be up-to-date on routine vaccinations before she becomes pregnant. The most effective way of protecting the infant against many diseases is to immunize the mother. Tetanus, diphtheria, and pertussis (Tdap) vaccine should be given during each pregnancy irrespective of the woman’s history of receiving Tdap. To maximize maternal antibody response and passive antibody transfer to the infant, optimal timing for Tdap administration is between 27 and 36 weeks of gestation, although it may be given at any time during pregnancy.
Annual influenza vaccine (inactivated) is recommended during any trimester for all women who are or will be pregnant during influenza season. For travelers, vaccination is recommended ≥2 weeks before departure if vaccine is available.
Certain vaccines, including meningococcal and hepatitis A and B vaccines that are considered safe during pregnancy, may be indicated based on risk. No adverse effects of inactivated polio vaccine (IPV) have been documented among pregnant women or their fetuses; however, vaccination of pregnant women should be avoided because of theoretical concerns. IPV can be administered in accordance with the recommended schedules for adults if a pregnant woman is at increased risk for infection and requires immediate protection against polio. Rabies postexposure prophylaxis with rabies immune globulin and vaccine should be administered after any moderate- or high-risk exposure to rabies; preexposure vaccine may be considered for travelers when the risk of exposure is substantial.
Most live-virus vaccines, including measles-mumps-rubella vaccine, varicella vaccine, and live attenuated influenza vaccine, are contraindicated during pregnancy; the exception is yellow fever vaccine, for which pregnancy is considered a precaution by the Advisory Committee on Immunization Practices (ACIP). If travel is unavoidable, and the risks for yellow fever virus exposure are felt to outweigh the risks of vaccination, a pregnant woman should be vaccinated. If the risks for vaccination are felt to outweigh the risks for yellow fever virus exposure, pregnant women should be issued a medical waiver to fulfill health regulations. Because pregnancy might affect immunologic function, serologic testing to document an immune response to yellow fever vaccine should be considered.
Postexposure prophylaxis of a nonimmune pregnant woman exposed to measles or varicella may be provided by administering immune globulin (IG) within 6 days for measles or varicella-zoster IG within 10 days for varicella.
Women planning to become pregnant should be advised to wait 4 weeks after receipt of a live-virus vaccine before conceiving. For certain travel-related vaccines, including Japanese encephalitis vaccine and typhoid vaccine, data are insufficient for a specific recommendation for use in pregnant women. A summary of current ACIP guidelines for vaccinating pregnant women is available at www.cdc.gov/vaccines/pregnancy/hcp/guidelines.html.
Malaria may be much more serious in pregnant than in nonpregnant women and is associated with high risks of illness and death for both mother and child. Malaria in pregnancy may be characterized by heavy parasitemia, severe anemia, and sometimes profound hypoglycemia, and may be complicated by cerebral malaria and acute respiratory distress syndrome. Placental sequestration of parasites may result in fetal loss due to abruption, premature labor, or miscarriage. An infant born to an infected mother is apt to be of low birth weight, and, although rare, congenital malaria is a concern.
Because no prophylactic regimen provides complete protection, pregnant women should avoid or delay travel to malaria-endemic areas. However, if travel is unavoidable, pregnant women should take precautions to avoid mosquito bites, and use of an effective prophylactic regimen is essential.
Chloroquine and mefloquine are the drugs of choice for pregnant women for destinations with chloroquine-sensitive and chloroquine-resistant malaria, respectively. Doxycycline is contraindicated because of teratogenic effects on the fetus after the fourth month of pregnancy. Primaquine is contraindicated in pregnancy because the infant cannot be tested for G6PD deficiency, putting the infant at risk for hemolytic anemia. Atovaquone-proguanil is not recommended because of lack of available safety data. A list of the available antimalarial drugs and their uses and contraindications during pregnancy can be found in Table 4-10 and in Chapter 4, Malaria.
Diane F. Morof, I. Dale Carroll