Flight crew work during pregnancy

What does the evidence say about flight crew work during pregnancy?

1. In a cohort of 2,273 flight attendants and 381 teachers covering 958 pregnancies, overall miscarriage risk was not increased among flight attendants compared with the teacher comparison group. 1
2. Within that same flight attendant cohort, flying 15 or more hours during home-base sleep hours was linked to a higher risk of first-trimester miscarriage (odds ratio 1.5), and high physical job demands carried an even larger association (odds ratio 2.5), while cosmic radiation exposure of 0.1 mGy or more showed a possible link to miscarriage in weeks 9 to 13 that did not reach statistical significance. 1
3. Occupational ionizing radiation guidance sets a general limit of 5 rem (50 mSv) per year for radiation workers, but once a pregnancy is declared to an employer, the recommended limit for the rest of the pregnancy drops to 500 millirem (5 mSv) total, with no more than about 50 millirem (0.5 mSv) in any single month; air travel work for pilots and flight attendants is explicitly named as one of the occupational settings where this applies. 2
4. An assessment of airline pilot logbooks found a median annual cosmic radiation dose of about 1.92 mSv in a recent study year, and the authors noted it would be possible for a female pilot, and potentially other flight crew, to exceed the international (ICRP) guideline of 1 mSv for the remainder of a pregnancy once it is declared, depending on route and schedule. 3
5. Data on cabin crew for international flights show average annual effective radiation doses of roughly 1.4 to 2.15 mSv in recent pre-pandemic years, dropping sharply during 2020 as flight volume fell, illustrating how directly crew-level dose tracks with actual hours flown rather than being a fixed yearly amount. 4

Is flight crew work safe in each trimester?

• First trimester. This is the highest-stakes window in the NIOSH cohort data: both long flying during normal sleep hours and high physical job demands were linked to more first-trimester miscarriages, and cosmic radiation exposure trended toward higher risk in weeks 9 to 13 specifically, though that particular radiation finding didn't reach statistical significance.
• Second trimester. Many airlines shift pregnant crew members to ground duty or lighter schedules by this point, and the cumulative radiation dose limit that applies once you declare your pregnancy to your employer is easier to stay under with reduced flight hours.
• Third trimester. Most airlines require flight attendants and pilots to stop flying well before the third trimester ends, both for radiation-dose management and practical reasons like cabin pressure changes and emergency evacuation duties. Confirm your specific airline's policy and timeline with occupational health.