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Can flying cause a miscarriage?

Many pregnant women need or want to travel by air at some point during their pregnancy, whether for work or personal reasons. It’s natural for expectant mothers to have concerns about whether flying could increase the risk of miscarriage. Miscarriage, also known as spontaneous abortion, is when a pregnancy ends unexpectedly before 20 weeks gestation. About 10-15% of known pregnancies end in miscarriage, usually in the first trimester. While the exact causes are often unknown, risk factors include things like chromosomal abnormalities, hormone issues, uterine abnormalities, infections, chronic conditions, and lifestyle factors like smoking, drug use, and excessive alcohol intake. Many women who experience miscarriage go on to have healthy pregnancies later.

Quick Summary

– For most healthy women with uncomplicated pregnancies, occasional air travel does not increase the risk of miscarriage. However, those with higher-risk pregnancies should consult their doctor first.

– The main potential concerns with flying while pregnant are low cabin air pressure, cosmic radiation exposure, security scanner radiation, dehydration, and developing blood clots. However, none have conclusively been linked to miscarriage.

– To be safe, some precautions pregnant travelers can take include staying hydrated, frequently moving/stretching, wearing compression stockings, getting aisle seats, and requesting a manual pat-down instead of going through security scanners.

How Could Flying Theoretically Increase Miscarriage Risk?

Although there is no conclusive evidence that flying directly increases miscarriage risk, there are some theoretical concerns related to air travel and pregnancy:

Lower cabin air pressure

Cabin air pressure drops as a plane gains altitude. Oxygen levels remain the same, but the lower air pressure means gases expand. For a pregnant woman, this could theoretically reduce flow of oxygenated blood to the fetus. However, studies on flight attendants who fly frequently have not found increased risk of miscarriage. For most short commercial flights, the pressure changes are unlikely to significantly impact a healthy pregnancy.

Cosmic radiation exposure

Air travelers are exposed to small amounts of cosmic ionizing radiation from outer space. At high doses, radiation is known to cause problems. However, the low amounts encountered during flights are thought to convey little to no increased risk to pregnant women or their fetuses, according to major health organizations. The occasional flight is safe, though frequent fliers or astronauts may exceed recommended limits.

Security scanners

Some potentially concerning rumors surround airport security scanners, like full-body X-ray scanners, but these scanners are considered safe in pregnancy as long as safety guidelines are followed. The extremely low dose of radiation from a single scan is negligible. However, the American College of Obstetricians and Gynecologists suggests pregnant women can opt for a manual pat-down instead if it gives them peace of mind.


Relative dehydration and immobility during long flights theoretically could increase the risk of conditions like deep vein thrombosis (DVT), which could impact circulation to the fetus. Staying properly hydrated and moving/stretching frequently can help minimize risks. Compression stockings are also recommended to improve circulation on long flights.

Developing blood clots

Pregnancy naturally increases the risk of developing blood clots due to hormone changes and reduced blood flow from pressure of the uterus. Long periods of immobility during air travel could further increase this risk. That’s why it’s important for expectant mothers on long flights to stay hydrated, limit alcohol, avoid tight clothing, get aisle seats for easier mobility, walk every hour or two, and consider compression stockings.

What do studies say about flying and miscarriage risk?

Despite the theoretical risks, most studies have found no significant link between air travel and miscarriage:

– A large 2013 study followed over 2,200 pregnant air travelers. About 9% had a miscarriage, consistent with normal rates. Flight duration did not affect risk.

– A 2002 survey of over 1,000 pregnant women found no difference in miscarriage rates between those who flew during pregnancy and those who did not.

– A 2001 study followed 131 pregnant flight attendants. Their miscarriage rate of 15% was no higher than the general population.

So for most healthy women with low-risk pregnancies, occasional flying appears safe. However, studies do show health factors like prior miscarriage, vaginal bleeding, carrying multiple fetuses, placental issues, maternal age, and pre-existing medical conditions can increase miscarriage risk. Women with high-risk pregnancies should discuss risks/benefits of air travel with their obstetric provider.

Are some types of flights riskier than others?

A few factors can impact theoretical risks:

Flight duration

Longer flights may increase risks related to immobility, dehydration, and exposure to lower air pressure and cosmic radiation. One study found potential, but inconclusive, evidence tying higher miscarriage risk to flights over 12 hours. Most experts say flights under 4 hours are safe, but moderate duration flights (4-6 hours) should include frequent movement and compression stockings as a precaution.

Trimester of pregnancy

The first trimester (weeks 0-13) may be most critical in terms of impact from radiation, pressure changes, and other stressors. Most experts consider flying safe after week 12-14 as risks decrease. After week 36, risks of going into early labor increase, so flying is not recommended late in pregnancy.

Frequent flying

Occasional air travel is fine, but risks may increase with very frequent flying. One study found flight attendants who flew more than 15 hours per week had higher miscarriage rates. Radiation exposure in particular can build up. Airlines have limits on flight hours for pregnant crew members.

Personal health

Women with risk factors for miscarriage like chronic health conditions, pregnancy complications, history of miscarriage, carrying multiples, and advanced maternal age may be advised to avoid air travel or take added precautions. Their providers can offer personalized recommendations.

Tips for safe, comfortable flying while pregnant

Here are some expert tips to minimize risks and have a smooth flight during pregnancy:

– Stay well hydrated before and during the flight. Avoid caffeine and alcohol, which contribute to dehydration.

– Request an aisle seat to facilitate moving about, stretching, and restroom access. Bulkhead seats also allow more leg room.

– Avoid empty bladder by using restroom frequently. A full bladder can aggravate pregnancy discomfort.

– Wear loose, breathable clothing. Avoid restrictive garments.

– Walk every hour or two to boost circulation. Perform calf stretches while seated. A short stroll through the cabin also helps prevent DVT.

– Consider graduated compression stockings to reduce swelling and improve circulation.

– Request a pat-down instead of going through airport security scanners if concerned about radiation. But scanners are deemed safe if used properly.

– Limit carry-on baggage weight to reduce strain. Ask for assistance loading heavy bags in overhead bins.

– Stay nourished. Eat small, healthy snacks and meals. Bring your own if concerned about airplane food.

– Try soothing remedies like peppermint or ginger tea to ease pregnancy nausea during flight.

– Bring a pillow or neck support. Use seat cushions or extra blankets for comfort.

– Check on airline policies related to pregnancy. Some require doctor approval for flying late in pregnancy.

– Consider travel insurance in case pregnancy complications arise away from home.

When should pregnant women avoid flying?

Some situations where air travel is not recommended during pregnancy:

– After week 36 for singleton pregnancies (after week 32 for multiples), when risks of preterm labor and delivery are higher

– For women at risk for preterm labor with symptoms like premature contractions

– When expecting mothers have medical conditions affected by changes in air pressure, like severe anemia or sickle cell disease

– For women experiencing third-trimester complications like preeclampsia, placental problems, bleeding, or ruptured membranes

– If pregnant women have any signs of illness, like active respiratory infections, they should postpone travel until recovered

– Following recent hospitalization related to the pregnancy

– If severe morning sickness makes adequate hydration difficult


For most healthy women, occasional air travel during an uncomplicated pregnancy is considered safe and is not thought to increase miscarriage risk. Some theoretical concerns exist like pressure changes, radiation, immobility, and dehydration, but studies have not conclusively linked these factors to miscarriage. Still, it’s smart to take precautions and discuss risks with your doctor if you have a high-risk pregnancy or must fly frequently. While flying is unlikely to cause miscarriage in a low-risk pregnancy, it can be an uncomfortable experience due to typical pregnancy symptoms. Following some comfort tips like hydration, compression socks, and aisle seating can help ease the journey. If you have any concerns about your specific situation, have an open discussion with your obstetric provider about the risks and benefits of air travel during pregnancy.