Answer to Question #12743 Submitted to "Ask the Experts"

Category: Pregnancy and Radiation — Flying

The following question was answered by an expert in the appropriate field:


I am currently five weeks pregnant and will be flying multiple long-haul flights when I will be seven to nine weeks pregnant. I am flying eight hours to Denmark and then eight hours to Canada and back. On my return flight back, it is two separate eight-hour flights with a 12-hour stop in Europe between the two. In all, I will have seven flights total for this trip. I will have another similar long-haul flight during my 30th week. 

I am concerned about the number of airports and flights, and the duration of both trips, and ultimately the total amount of radiation that I and the baby will be exposed to on these trips.


The amount of radiation exposure from flying is significantly lower than the exposure needed to cause harmful effects to an embryo/fetus.

As noted in Hall and Giaccia (2006) and Wagner et al. (1997), the dose needed to cause harmful effects for an embryo/fetus is on the order of 100 millisievert (mSv). Radiation during commercial flight is on the order of 0.01–0.02 mSv per hour of flying time. This means you would need to fly on 1,000 trips of 10 hours each during pregnancy to receive the amount of radiation that might be harmful.

Here are some links to other questions and answers on the website concerning pregnancy: ATE Q/A 11887, ATE Q/A 11481 plus an FAQ on pregnancy and flying that may also be of interest. :

Kelly Classic
Certified Medical Health Physicist

Hall EJ, Giaccia AJ. Radiobiology for the radiologist. 6th ed. New York: Lippincott Williams & Wilkins; 2006.

Wagner LK, Lester RG, Saldana LR. Exposure of the pregnant patient to diagnostic radiations. 2nd ed. Madison, Wisconsin: Medical Physics Publishing; 1997.

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 7 December 2018. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.