Pregnant Travelers | Yellow Book

Introduction

Pregnancy can cause physiologic changes that require special consideration during travel. With careful preparation, however, safe travel is possible during pregnancy.

Pre-travel consultation

The pre-travel consultation and evaluation of pregnant travelers begins with a careful medical and obstetric history, specifically assessing gestational age and identifying factors and conditions that increase risk for adverse pregnancy outcomes (Box 6.1.1). Include a visit with an obstetric healthcare professional as part of the pre-travel assessment to ensure routine prenatal care and to identify pregnancy-related health problems. Instruct pregnant travelers to carry with them a copy of their prenatal records and healthcare professional’s contact information.

Review the pregnant traveler’s itinerary, including accommodations, activities, and destinations, to guide pre-travel health advice. Discourage pregnant travelers from undertaking unaccustomed vigorous activity. Swimming and snorkeling during pregnancy are generally safe. Data are insufficient to establish absolute safety of scuba diving during pregnancy; data from animal studies suggest possible adverse fetal effects from fetal decompression illness and hyperbaric oxygen exposure. Scuba diving is best avoided during pregnancy due to possible fetal risks (see Scuba Diving: Decompression Illness and Other Dive-Related Injuries chapter). Riding animals, bicycles, or motorcycles presents risks for falls, accidents, and abdominal trauma. Falls during waterskiing also can result in abdominal trauma.

Educate pregnant travelers on how to avoid travel-associated risks, manage minor pregnancy discomforts, and recognize serious complications. Advise pregnant travelers to seek immediate medical attention if they experience any urgent maternal warning signs or symptoms and to make sure that their pregnancy status is known to any healthcare professional they see for care (Box 6.1.2).

Box 6.1.1

Box 6.1.2

Contraindications to travel during pregnancy

Absolute contraindications to travel are conditions for which the potential harm of travel during pregnancy always outweighs the benefits of travel to the pregnant traveler or her fetus. Relative contraindications are conditions for which travel should be avoided if the potential harm from travel outweighs its benefits (Box 6.1.3).

Travel rarely is contraindicated during a normal pregnancy. Pregnancies that require frequent antenatal monitoring or close medical supervision might warrant a recommendation that travel be postponed. Risk of obstetric complications is greatest in the first and third trimesters of pregnancy.

Box 6.1.3

Planning for emergency obstetric care

Obstetric emergencies are often sudden and life-threatening. Advise all pregnant travelers (but especially those in their third trimester or otherwise at high risk) to identify, in advance, medical facilities at their destination(s) capable of managing complications of pregnancy, delivery (including by caesarean section), and neonatal problems. Counsel against travel to areas where obstetric care and neonatal care might not be able to meet the needs for their individual pregnancy and neonatal health risks. Review urgent maternal warning signs (Box 6.1.2).

Many health insurance policies do not cover the cost of medical treatment for pregnancy or neonatal complications that occur outside the United States. Pregnant travelers should strongly consider purchasing primary or supplemental travel health insurance that covers pregnancy-related problems and care of the neonate. Medical evacuation insurance coverage is also advised in case of pregnancy-related complications (see Travel Insurance, Travel Health Insurance, and Medical Evacuation Insurance chapter).

Medications

Various systems are used to classify drugs with respect to their safety in pregnancy. Refer to specific data about the effects of a given drug during pregnancy rather than depending on a classification. Counsel pregnant travelers to help them make a balanced decision on the use of medications.

Over-the-counter drugs and non-drug remedies can help make travel more comfortable during pregnancy. Pregnant travelers can safely use a mild bulk laxative for constipation. Several simple remedies are effective in relieving the symptoms of morning sickness, such as non-prescription remedies that include ginger, such as fresh ground ginger or powder that can be mixed with food or drinks (e.g., tea), and as candy (e.g., lollipops). Pyridoxine (vitamin B6) is effective in reducing symptoms of morning sickness and is available in tablet form, as well as lozenges and lollipops. Antihistamines (e.g., dimenhydrinate, meclizine) often are used in pregnancy for morning sickness and motion sickness and appear to have a good safety record. Advise pregnant travelers with morning sickness to seek medical attention if they are unable to drink sufficient fluids and stay hydrated. Acetaminophen remains the non-opioid analgesic of choice during pregnancy.

Advise patients to exercise caution in purchasing medications and herbal supplements, as safety regulations may vary by travel destination. Reputable sources, such as pharmacies, are preferred, and open markets should be avoided for purchase of medications and herbal supplements. Travelers should know medication contents and only take medications that have an intact safety seal.

Vaccinations

The most effective way of keeping pregnant women and their infants healthy is through vaccination. Ideally, vaccinations should be up to date before pregnancy, and immunizations indicated for pregnant women should be administered at appropriate times during pregnancy (see Advisory Committee on Immunization Practices guidelines for vaccinating pregnant women). Pregnant women can take acetaminophen if they experience fever or other post-vaccination symptoms.

Coronavirus disease 2019

COVID-19 vaccination can be provided safely before pregnancy or during any trimester of pregnancy (see COVID-19 chapter). Available vaccines are highly effective in preventing severe COVID-19, hospitalization, and death; vaccination during pregnancy benefits both the pregnant woman and her fetus. Side effects from COVID-19 vaccination in pregnant women are like those expected among non-pregnant women.

Hepatitis A and hepatitis B

The limited data available on the safety of hepatitis A vaccination during pregnancy showed no increased risk of adverse events in pregnant women and their infants. Risk to the developing fetus is expected to be low because hepatitis A vaccine is produced from inactivated virus. Pregnant women at risk of hepatitis A virus (HAV) infection or at risk for severe outcomes from HAV should be vaccinated during pregnancy. Risk factors for infection include international travel along with injection or non-injection drug use, occupational risk for infection, close personal contact with an international adoptee, or experiencing homelessness (see Hepatitis A chapter). Pregnant women at risk for severe outcomes from HAV infection include those with chronic liver disease or living with HIV infection.

Limited data suggest that developing fetuses are not at risk for adverse events resulting from vaccination of pregnant women against hepatitis B. Pregnant women should be vaccinated with hepatitis B vaccine if not previously vaccinated.

Influenza

Influenza vaccine is recommended for pregnant women and can be administered during any trimester of pregnancy.

Japanese encephalitis

Pregnancy is a precaution for use of Japanese encephalitis (JE) vaccine (see Japanese Encephalitis chapter). Vaccination usually should be deferred because of a theoretical risk for the developing fetus. Pregnant women who must travel to an area where risk for JE is high should be vaccinated if benefits outweigh risks of vaccination to the mother and developing fetus.

Live-virus vaccines

Most live-virus vaccines, including live attenuated influenza, measles-mumps-rubella, live typhoid (Ty21a), and varicella, are contraindicated during pregnancy. Advise women planning to become pregnant to wait 28 days after receipt of a live-virus vaccine before conceiving. Post-exposure prophylaxis of a non-immune pregnant woman exposed to measles can be provided by administering intravenous immunoglobulin within 6 days of exposure. Post-exposure prophylaxis after varicella exposure can be provided with varicella-zoster immune globulin, which should be administered as soon as possible after exposure and within 10 days (see Measles (Rubeola) chapter).

Meningococcal

Pregnant travelers should receive quadrivalent meningococcal vaccine, if indicated, depending on risk for infection at the destination (see Meningococcal Disease chapter).

Polio

No adverse events linked to inactivated polio vaccine (IPV) have been documented among pregnant women or their fetuses. IPV can be administered to a pregnant woman at increased risk for infection who requires immediate protection against polio, although vaccination of pregnant women not at increased risk should be avoided because of theoretical concerns (see Poliomyelitis chapter).

Rabies

Administer rabies post-exposure prophylaxis with rabies immune globulin and vaccine after any moderate- or high-risk exposure to rabies; consider pre-exposure prophylaxis for travelers who have a substantial risk for exposure (see Rabies chapter).

Respiratory syncytial virus

Respiratory syncytial virus (RSV) vaccine is recommended during weeks 32 through 36 of pregnancy, administered immediately before or during RSV season. As of early 2025, only one, ABRYSVO (Pfizer), of the available RSV vaccines is licensed for use in pregnancy. In the United States, vaccine is recommended during September–January in most locations, although for travel to other locations, timing may vary as RSV circulation may differ from that typical of most of the continental United States.

Tetanus-diphtheria-pertussis

Tetanus, diphtheria, and acellular pertussis vaccine (Tdap) should be given during each pregnancy irrespective of a woman’s history of receiving the vaccine previously. To maximize maternal antibody response and passive antibody transfer to the infant, optimal timing for Tdap administration is 27–36 weeks gestation (earlier during this time frame is preferred), but it may be given at any time during pregnancy.

Typhoid fever

Currently available vaccines include a live-attenuated vaccine and a polysaccharide vaccine (see Typhoid and Paratyphoid Fever chapter). There are no data regarding the use of either typhoid vaccine in pregnancy. While the live-virus vaccine is contraindicated during pregnancy, the polysaccharide vaccine may be given to pregnant women if clearly needed, based upon risk for exposure.

Yellow fever

Yellow fever vaccine is the exception to the rule about live-virus vaccines being contraindicated during pregnancy; pregnancy is a precaution (i.e., a relative contraindication) for yellow fever vaccine. If travel is unavoidable, and the risk for yellow fever virus exposure outweighs the vaccination risk, it is appropriate to recommend vaccination. If the risks for vaccination outweigh the risks for yellow fever virus exposure, consider providing a medical waiver to the pregnant traveler to fulfill health regulations. Because pregnancy might affect immune responses to vaccination, serologic testing can be done to document an immune response if sufficient time and if the result would alter travel plans. If a woman was pregnant (regardless of trimester) when she received her initial dose of yellow fever vaccine, she should receive 1 additional dose before she is next at risk for yellow fever virus exposure (see Yellow Fever chapter).

Travel health kits

Pregnant travelers should consider packing antacids, antiemetic drugs, graduated compression stockings, hemorrhoid cream, medication for vaginitis or yeast infection, prenatal vitamins, and prescription medications in addition to the recommended travel health kit items for all travelers (see Travel Health Kits chapter). Some travelers might consider packing a blood pressure monitor or other medical equipment (e.g., spirometer, glucometer) as recommended by their obstetric healthcare professional.

Infectious disease concerns

Respiratory infections

Pregnant women are at increased risk of severe illness from respiratory infections compared to non-pregnant women. Early treatment may prevent severe illness and complications. Pregnant travelers are encouraged to seek medical care for signs and symptoms that could indicate worsening illness or of another life-threatening situation (Box 6.1.2).

Influenza

Influenza may be associated with risk of adverse outcomes in pregnant women, including hospitalization, admission to an intensive care unit, and death (see Influenza chapter). Prevention measures include vaccination, avoiding contact with people who are sick, wearing a mask, and hand hygiene. Clinical presentation and diagnosis are the same as in non-pregnant women. Treatment with appropriate antiviral medications (e.g., oseltamivir 75 mg orally twice daily for 5 days) is indicated for pregnant women and those up to 2 weeks postpartum with acute influenza.

Coronavirus disease 2019

Pregnant women are at increased risk for severe COVID-19-associated outcomes, including severe illness, death, and adverse birth outcomes, including preterm birth, compared with women who are not pregnant (see COVID-19 chapter). Pregnant and recently pregnant women and those who live with or visit them should take steps to protect themselves from getting COVID-19, including wearing a mask and staying up to date with COVID-19 vaccination. Pregnant travelers are encouraged to contact a healthcare professional within 24 hours of developing symptoms of COVID-19 for information on further evaluation and treatment.

Urinary tract infections

Urinary tract infections occur commonly during pregnancy, and untreated infections in pregnant women can be associated with increased risk of preterm birth, low birth weight, or perinatal mortality. Pregnant women may become ill and are at risk for medical (e.g., sepsis, respiratory failure) and obstetrical complications from pyelonephritis.

Providers should be aware of special considerations for treatment of urinary tract infections in pregnant women. Treatment with either nitrofurantoin or trimethoprim-sulfamethoxazole is typically avoided in the first trimester of pregnancy, and trimethoprim-sulfamethoxazole is avoided near term. Aminoglycosides have been associated with ototoxicity following prolonged fetal exposure, and fluroquinolones generally are not used during pregnancy.

Gastrointestinal infections

Pregnant travelers with diarrhea or other gastrointestinal infections might be more vulnerable to dehydration than non-pregnant travelers. Stress the need for strict hand hygiene and food and water precautions (see Food and Water Precautions for Travelers chapter). Drinking bottled or boiled water is preferable to avoid pathogens that might not be eliminated by chemically treated or filtered water. Pregnant travelers should not consume water purified by iodine-containing compounds because of potential fetal thyroid effects (see Water Disinfection for Travelers chapter).

Travelers’ diarrhea

The treatment of choice for travelers’ diarrhea is prompt and vigorous oral hydration; azithromycin or a third-generation cephalosporin may be given to pregnant travelers if clinically indicated (see Travelers’ Diarrhea and Post-Travel Diarrhea chapters). Avoid use of bismuth subsalicylate because of the potential impact of salicylates on the fetus. Fluoroquinolones are generally avoided in pregnancy to avoid potential toxicity to developing cartilage, though therapeutic doses during pregnancy are unlikely to pose a substantial teratogenic risk as noted in the U.S. Food and Drug Administration information regarding use.

Hepatitis

Hepatitis A and hepatitis E are both spread by the fecal-oral route (see Hepatitis A chapter). Hepatitis A has been reported to increase the risk for placental abruption and premature delivery. Hepatitis E is more likely to cause severe disease during pregnancy and has a case-fatality rate of 15%–25%. When acquired during the third trimester, hepatitis E is associated with fetal complications and fetal death. Acute hepatic failure occurs more frequently when hepatitis E infection occurs during pregnancy. Poor outcomes in pregnancy may also be due in part to poor nutritional status and lack of access to supportive medical care in the settings from which data have been reported.

Listeriosis and toxoplasmosis

Listeriosis and toxoplasmosis are foodborne illnesses of particular concern during pregnancy because the infection can cross the placenta and cause spontaneous abortion, stillbirth, or congenital or neonatal infection. Risk for fetal infection increases with gestational age, but severity of infection is decreased. Warn pregnant travelers to avoid unpasteurized cheeses and uncooked or undercooked meat products.

Parasitic infections and diseases

Intestinal helminths rarely cause enough illness to warrant treatment during pregnancy, and most can be addressed safely with symptomatic treatment until the pregnancy is over. Protozoan intestinal infections (e.g., Cryptosporidium, Entamoeba histolytica, Giardia) often do require treatment. These parasites can cause acute gastroenteritis, severe dehydration, and chronic malabsorption resulting in fetal growth restriction (see Post-Travel Parasitic Disease Including Evaluation of Eosinophilia chapter). E. histolytica can cause invasive disease, including amebic liver abscess and colitis. Pregnant travelers should avoid bathing, swimming, or wading in freshwater lakes, rivers, and streams that can harbor the parasitic worms (larval schistosomes) that cause schistosomiasis (see Schistosomiasis chapter). Pregnant travelers should avoid walking barefoot on soil or sand (e.g., beaches) that may be contaminated with soil-transmitted helminths that penetrate the skin (hookworm and Strongyloides).

Vector-borne infections

Pregnant travelers should avoid mosquito bites. Preventive measures include use of Environmental Protection Agency–registered insect repellents, protective clothing, and mosquito nets (see Mosquitoes, Ticks, and Other Arthropods chapter). Details on yellow fever vaccine, Japanese encephalitis vaccine, and malaria prophylaxis during pregnancy are provided elsewhere in this chapter.

Zika

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 can be asymptomatic or mild; some patients report acute onset of conjunctivitis, fever, joint pain, or rash that lasts for several days to a week after infection (see Zika chapter). Serologic testing for Zika infection has limitations and is not recommended routinely for asymptomatic pregnant women.

Birth defects caused by Zika virus infection during pregnancy include brain, eye, and neurodevelopmental abnormalities. Pregnant women should reconsider travel to areas with a Zika outbreak, and, for the duration of the pregnancy, avoid sex or use condoms with anyone who has traveled to a risk area. The most current list of countries and territories where Zika is active; guidance for pregnant women.

Oropouche

Healthcare providers should be aware of the risk of vertical transmission and possible adverse impacts on the fetus, including fetal death or congenital abnormalities. Inform pregnant patients of the possible risks to the fetus when considering travel to areas with reported Oropouche virus transmission. Counsel these patients to consider the destination, reason for traveling, and their ability to prevent insect bites. Pregnant women are currently recommended to reconsider non-essential travel to areas with a Level 2 Travel Health Notice for Oropouche. If a pregnant woman decides to travel, counsel her to strictly prevent insect bites during travel. For the latest information, see Clinical Overview of Oropouche Virus Disease and Oropouche and Pregnancy.

Chikungunya and dengue

Prevention of mosquito bites is important for prevention of other arboviral infections, including chikungunya virus and dengue virus infections, both of which are also carried by Aedes mosquitos (see Chikungunya and Dengue chapters). Adverse fetal outcomes have been noted with both of these infections during pregnancy. Therefore, pregnant women should also reconsider travel to areas with outbreaks of chikungunya or dengue.

Malaria

Malaria, caused by Plasmodium spp. parasites transmitted by mosquitoes, can be much more serious in pregnant than in non-pregnant women and is associated with high risks of illness and death for both mother and fetus. Malaria in pregnancy can be characterized by heavy parasitemia, severe anemia, and profound hypoglycemia and can be complicated by cerebral malaria and acute respiratory distress syndrome. Placental sequestration of parasites might 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 possible.

Pregnant women should avoid or delay travel to malaria-endemic areas if possible because no prophylactic regimen provides complete protection. If travel is unavoidable, the pregnant woman should take precautions to avoid mosquito bites and use an effective prophylactic regimen.

Chloroquine is the drug of choice for pregnant travelers going to destinations with chloroquine-sensitive Plasmodium spp., and mefloquine is the drug of choice for pregnant travelers going to destinations with chloroquine-resistant Plasmodium spp. Doxycycline is contraindicated because of teratogenic effects on the fetus after the fourth month of pregnancy. Primaquine and tafenoquine are contraindicated in pregnancy because the infant cannot be tested for glucose-6-phosphate dehydrogenase deficiency, putting the infant at risk for hemolytic anemia. Atovaquone-proguanil is not recommended because of lack of safety data. A list of the available antimalarial drugs and their uses and contraindications during pregnancy can be found in Malaria chapter.

Environmental health concerns

Pregnant travelers should be aware of current environmental health issues related to their destinations and activities (e.g., air quality, extreme heat, high elevation travel, severe weather emergencies, and natural disasters). More information can be found at the CDC Travelers’ Health website and on the destination pages of the U.S. Department of State website.

Air quality

Air pollution can cause more health problems during pregnancy because ciliary clearance of the bronchial tree is slowed and mucus is more abundant. Emerging evidence suggests association of air pollution exposure with exacerbation of maternal respiratory disease (e.g., asthma) and fetal growth effects (e.g., fetal growth restriction and low birth weight). For more details on traveling to destinations where air quality is poor, see Air Quality and Ionizing Radiation During Travel.

Wildfire smoke contains particulate matter, which may include lung irritants, carcinogens, and neurotoxicants depending on items burned. Pregnant travelers should avoid wildfire smoke exposure (staying indoors, keeping windows and doors closed, and turning on HVAC or a portable air filtration unit) as much as possible. If wildfire smoke exposure is unavoidable, pregnant travelers should monitor air quality reports and follow instructions about exercise and going outside for “sensitive individuals” or other special population designation. When it is not possible to avoid exposure to wildfire smoke, pregnant travelers should consider using an N95 respirator.

Carbon monoxide

Carbon monoxide (CO) is a colorless, odorless, tasteless gas produced from gas- and oil-burning furnaces, portable generators, charcoal grills, heaters, or stoves in enclosed areas (see Poisonings, Envenomations, and Toxic Exposures During Travel chapter). Symptoms of CO poisoning include headache, dizziness, nausea, vomiting, shortness of breath, or loss of consciousness. Fetal hemoglobin has higher affinity for CO than adult hemoglobin. CO poisoning in pregnancy may be linked to adverse fetal outcomes, including congenital malformation, severe neurologic sequelae, fetal growth restriction, or intrauterine fetal death. Pregnant travelers should be aware of symptoms of CO poisoning and minimize exposure to sources of CO.

Extreme heat

Body temperature regulation is not as efficient during pregnancy, and extreme heat can create more physiological stress on the pregnant woman (see Heat and Cold Illnesses in Travelers chapter). Pregnant women are likely to get heat exhaustion, heat stroke, or other heat-related illness sooner than non-pregnant women and are more likely to become dehydrated. The vasodilatory effect of a hot environment and dehydration might cause fainting and subsequent risk for falls or injury (including abdominal trauma). Encourage pregnant travelers to seek air-conditioned accommodations, attend a designated public cooling center if necessary, restrict their level of activity in hot environments, and avoid dehydration. If heat exposure is unavoidable, the duration should be as short as possible to prevent an increase in core body temperature. Increased internal temperature and fever during pregnancy have been linked to birth defects and other pregnancy complications. Medical care should be sought immediately if the pregnant traveler experiences symptoms of heat-related illness.

High-altitude travel

Pregnant travelers should avoid activities at high elevation unless they have trained for and are accustomed to such activities. Cardiopulmonary demands are increased normally during pregnancy, and those not acclimated to high elevation and lower atmospheric oxygen levels might experience new or worsening symptoms of breathlessness and palpitations. Common symptoms of high-altitude illness (e.g., headache, fatigue, insomnia, or nausea) frequently are associated with pregnancy, and it might be difficult to distinguish the cause of the symptoms. Recognition and response to early signs and symptoms of high-altitude illness may avoid complications.

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 elevations during pregnancy. Probably the greatest concern is that high-elevation destinations often are inaccessible and far from medical care (see High-Altitude Travel and Altitude Illness chapter).

Natural disasters and severe weather emergencies

Pregnant travelers may encounter hazards from unexpected natural disasters or severe weather emergencies. Immediate adverse health risks are associated with trauma, decreased access to health care (e.g., for labor or for trauma), and with exposure to toxic (e.g., chemical spill) or infectious materials (e.g., mold, contaminated water). Resources about what to do in crisis, disaster, or emergency situations while traveling abroad are available from the U.S. Department of State. Pregnant travelers should pay attention to announcements from emergency officials about disasters and severe weather emergencies, including alerts about safety (e.g., wildfire alerts and flood warnings) and actions (e.g., evacuation alerts and boil water advisories). Potentially contaminated materials (e.g., flood water) and hazards (e.g., damaged buildings, mold, cleaning solvents) should be avoided if at all possible.

During an unexpected natural disaster or severe weather emergency, the pregnant traveler may have to stay at a shelter or other temporary housing. It is generally good practice to ensure that shelter staff are aware that the traveler is pregnant. The pregnant traveler should seek immediate care for signs of labor or other urgent maternal warning signs (Box 6.1.2). For more information, see Safety Messages for Pregnant, Postpartum, and Breastfeeding Women During Natural Disasters and Severe Weather.

Transportation considerations

Pregnant travelers should follow safety instructions for all forms of transport and wear seat belts, when available, on all forms of transportation, including airplanes, buses, and cars (see Injury and Death During Travel chapter). 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 gravid abdomen and across the upper thighs, not above or across the gravid abdomen.

Air travel

Most commercial airlines allow pregnant travelers to fly until 36 weeks’ gestation (see Air Travel chapter). 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 and should consider the gestational age of the fetus on both departure and return dates.

Most commercial jetliner cabins are pressurized to an equivalent outside air pressure of 1,800–2,500 m (approximately 6,000–8,000 ft) above sea level; travelers might also experience air pressures in this range during travel by hot air balloon or on non-commercial aircraft. The lower oxygen tension under these conditions likely will not cause fetal problems in a normal pregnancy. Women with pregnancies complicated by conditions exacerbated by hypoxia (e.g., preexisting cardiovascular problems, sickle cell disease, severe anemia (hemoglobin

Risks of air travel include potential exposure to communicable diseases, immobility, and the common discomforts of flying. Abdominal distention may worsen during flights, and pedal edema frequently occurs. The pregnant traveler might benefit from an upgrade in airline seating and should seek convenient and practical accommodations (e.g., proximity to the lavatory). Pregnant travelers should consider selecting aisle seating when possible and wearing loose-fitting clothing and comfortable shoes that enable them to move about more easily and frequently during flights.

Some experts report that the risk for deep vein thrombosis (DVT) is at least 5 times greater among pregnant than non-pregnant women, although the absolute risk is low. To help prevent DVT, pregnant travelers should stay hydrated, stretch frequently, walk and perform isometric leg exercises, and wear graduated compression stockings (see Deep Vein Thrombosis and Pulmonary Embolism chapter).

Cosmic radiation during air travel poses little threat to the fetus but might be a consideration for pregnant travelers who fly frequently. Older airport security machines are magnetometers and are not harmful to the fetus. Airport security machines use either millimeter-wave or x-ray backscatter scanners, which emit low levels of radiation. Most experts agree that the risk for complications from radiation exposure from these scanners is extremely low.

Cruise ship travel

Most cruise lines restrict travel beyond 24 weeks’ gestation (see Cruise Ship Travel chapter). Cruise lines may require pregnant travelers to carry a physician’s note stating that they are fit to travel and the pregnancy is not high-risk (must include the estimated date of delivery). Pregnant travelers should check with the cruise line for specific requirements or guidance. Travel health risks during cruises include gastrointestinal and respiratory infections, motion sickness, falls on a moving vessel, and the possibility of delayed care while at sea (see Motion Sickness chapter).

Acknowledgements

The following authors contributed to the previous version of this chapter: I. Dale Carroll and Titilope Oduyebo.