Answer to Question #14012 Submitted to "Ask the Experts"

Category: Pregnancy and Radiation — Exposures to embryo/fetus

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


Unaware of her pregnancy, my wife underwent lung computed tomography (CT) scans twice within a week for testing COVID-19. She was almost three weeks pregnant at the time. The hospital didn't use lead shields while performing scans. I'm not sure of the dose used. Will there be harm to baby due to these scans?


First, I would like to let you know that the dose to the baby from one chest CT would generally be no more than about 0.2 milligray (mGy) of absorbed radiation dose. If your wife underwent two of these scans, the dose to the baby would still only be about 0.4 mGy. The risks to an embryo or fetus of any age are very small at doses less than 100 mGy and negligible at doses of less than 50 mGy. You may want to read more about radiation exposure and pregnancy in the Health Physics Society information sheet on pregnancy and radiation exposure.

Also, many institutions in the United States have stopped using lead to shield pregnant women, because it does not actually increase the safety. The American Association of Physicists in Medicine has recently published a position statement on use of patient gonadal and fetal shielding.  

I hope this helps to answer your question, and my best wishes to you and your family. 

Barbara Hamrick, CHP

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 2 June 2021. 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.