Flying while pregnant
Talk to your doctor or midwife before you fly. Flying is not harmful in a straightforward pregnancy, but each airline sets its own limit on how many weeks you can fly, and later in the pregnancy you may need a letter. On the plane, the seat belt goes under your bump.
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Updated October 2026
Ask your doctor or midwife first
This is the first thing to do, before anything else on this page. The NHS says that flying is not harmful to you or your baby, but that you should discuss any health issues or pregnancy complications with your midwife or doctor before you fly, and MedlinePlus says the same: it is still a good idea to talk to your provider if you are planning a trip.
The same goes for the airline. Avianca's own page opens by saying that it is important that you consult with your doctor if flying during your pregnancy is the safest and most convenient option, and United Airlines suggests speaking to your doctor before you fly. A letter can take time to arrange, and the NHS notes that you may have to wait several weeks to get one.
The week limits are each airline's own
There is no single limit. The NHS explains that the chance of going into labour is naturally higher after 37 weeks, and that some airlines will not let you fly towards the end of your pregnancy, so the airline's own policy is the one to check. Three examples from the airlines' own pages:
- American Airlines: if your due date is within 4 weeks of your flight, you must provide a doctor's certificate stating that you have been recently examined and are fit to fly.
- United Airlines: you may need medical clearance if you are flying at 36 weeks pregnant or if the pregnancy is high-risk, with a doctor's note dated within 72 hours of departure confirming that you are fit to fly and that your delivery date is after your travel dates.
- Avianca: from 30 weeks you present a medical certificate at the counter for each flight, stating the estimated delivery date and that you can travel safely by air, and the certificate must be less than 10 days old. For the safety of mother and baby, flying is not possible after 36 weeks.
The NHS also notes that after week 28 an airline may ask for a letter from your doctor or midwife confirming your due date and that you are not at risk of complications, so it is worth asking what the airline will want before you book.
On the plane: the seat belt and moving about
The seat belt goes low. The Royal College of Obstetricians and Gynaecologists is clear that you must wear a seatbelt, with the strap fastened reasonably tightly across the top of your thighs and then under your bump, and you can ask the cabin crew for a seatbelt extension if you need one.
Move about, and have plenty of water. A flight of more than four hours carries a small risk of blood clots, and being pregnant and sitting still both raise that risk, so the NHS advises taking plenty of water and moving about regularly, every 30 minutes or so, and MedlinePlus says to get up and walk every hour, which helps circulation and keeps swelling down.
On a medium or long haul flight the RCOG adds: wear loose clothing and comfortable shoes, try to get an aisle seat and take regular walks around the plane, do in-seat exercises every 30 minutes or so, have cups of water at regular intervals, keep away from coffee and fizzy drinks, and wear graduated elastic compression stockings, which need to be the right size and type for you.
Before you travel
MedlinePlus's list is short and worth following: eat as you normally do, drink plenty of fluids, wear comfortable shoes and clothing that is not tight, bring a copy of your prenatal care records, and get up and walk every hour. It also advises taking crackers and juice with you to avoid nausea.
And the NHS advises that the best time to travel is often mid-pregnancy, between 4 and 6 months, because travelling in the final months can be tiring and uncomfortable. Check what the airline needs, ask your doctor or midwife, and leave time for a letter if one is required.
Sources
- Travelling in pregnancy, of the NHS: flying is not harmful to you or your baby, but discuss any health issues or pregnancy complications with your midwife or doctor before you fly. The chance of going into labour is naturally higher after 37 weeks, and some airlines will not let you fly towards the end of your pregnancy, so check with the airline. After week 28 the airline may ask for a letter from your doctor or midwife confirming your due date and that you are not at risk of complications. Long-distance travel of more than 4 hours carries a small risk of blood clots, so if you fly, drink plenty of water and move about regularly, every 30 minutes or so. — nhs.uk (checked 21 October 2026)
- Air travel and pregnancy, of the Royal College of Obstetricians and Gynaecologists: you must wear a seatbelt, with the strap fastened reasonably tightly across the top of your thighs and then under your bump, and you can ask the cabin crew for a seatbelt extension. On a medium or long haul flight of over four hours, it advises loose clothing and comfortable shoes, an aisle seat and regular walks around the plane, in-seat exercises every 30 minutes or so, cups of water at regular intervals, cutting down on drinks with caffeine, and graduated elastic compression stockings. — rcog.org.uk (checked 21 October 2026)
- Pregnancy and travel, of MedlinePlus, the U.S. National Library of Medicine: most of the time it is fine to travel while pregnant, and it is still a good idea to talk to your provider if you are planning a trip. When you travel you should eat as you normally do, drink plenty of fluids, wear comfortable shoes and clothing that is not tight, bring a copy of your prenatal care records, and get up and walk every hour, which helps circulation and keeps swelling down, because being inactive for long periods and being pregnant both increase the risk of blood clots in the legs and lungs. — medlineplus.gov (checked 21 October 2026)
- Traveling with children, of American Airlines: if your due date is within 4 weeks of your flight, you must provide a doctor's certificate stating that you have been recently examined and are fit to fly. — aa.com (checked 21 October 2026)
- Flying while Pregnant, of United Airlines: you may need medical clearance if you are flying at 36 weeks pregnant or if the pregnancy is high-risk, and the airline suggests a doctor's note dated within 72 hours of departure, stating that the doctor has cleared you as physically fit for air travel during your travel dates and duration of the flight, and that the estimated date of delivery is after your travel dates. — united.com (checked 21 October 2026)
- Can I fly while pregnant?, in the help centre of Avianca: you can fly while you are pregnant, but it depends on how many weeks you are, and it is important that you consult with your doctor if flying is the safest and most convenient option. For a pregnancy of 30 weeks or more, you present at the airport counter for each flight a medical certificate that specifies the estimated date of delivery and that you can travel safely by air, and all certificates must be less than 10 days old. For the safety of both the mother and the baby, it will not be possible to fly after 36 weeks of pregnancy. — ayuda.avianca.com (checked 21 October 2026)
Frequently asked questions
Is it safe to fly while pregnant?
The NHS says flying is not harmful to you or your baby, but that you should discuss any health issues or pregnancy complications with your midwife or doctor before you fly. Ask your doctor or midwife before you travel.
How many weeks can I fly at?
Each airline sets its own limit. American Airlines asks for a doctor's certificate if your due date is within 4 weeks of the flight, United Airlines may need medical clearance at 36 weeks or in a high-risk pregnancy, and Avianca does not allow flying after 36 weeks. The NHS notes that some airlines will not let you fly towards the end of your pregnancy.
Will I need a doctor's letter?
It depends on the airline and on how many weeks you are. The NHS says that after week 28 an airline may ask for a letter from your doctor or midwife confirming your due date and that you are not at risk of complications. Avianca asks for a medical certificate from 30 weeks for each flight, and United asks for a note dated within 72 hours of departure.
How should I wear the seat belt when pregnant?
The Royal College of Obstetricians and Gynaecologists says you must wear a seatbelt, with the strap fastened reasonably tightly across the top of your thighs and then under your bump, and you can ask the cabin crew for a seatbelt extension if you need one.
What should I do on a long flight while pregnant?
Drink plenty of water and move about regularly, every 30 minutes or so, and get up and walk every hour. The RCOG also advises loose clothing and comfortable shoes, an aisle seat if you can get one, in-seat exercises every half hour, keeping away from coffee and fizzy drinks, and graduated compression stockings of the right size and type.