Answer to Question #6119 Submitted to "Ask the Experts"

Category: Pregnancy and Radiation — Exposures not directly to embryo/fetus

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


My sister-in-law is 22 weeks pregnant. She was standing next to her five-year-old son when he was having a CT (computed tomography) brain scan. She was not wearing a lead apron at the time of the scan. Can you tell me the risks to the baby? I understand that after 20 weeks, radiation risk to the unborn baby is no more than for the mother, but in this case she was not wearing a lead apron. This is the main concern.


Thank you for your question. It would be difficult to estimate how much radiation exposure your sister-in-law or her baby received, but I can say that it would not have been enough to cause health effects for either one. 

The only radiation she would have been exposed to would have been scatter radiation and, depending on how close she was to the CT scanner, this was probably about 1% or less of the radiation dose her son received. It would have been very small and even smaller if she were not very close to the scanner.

I would recommend, however, that should she ever have to be in the room again while an x ray is being taken, she request a lead apron whether she is pregnant or not. In the United States, it is a requirement for anyone in the room.

Kelly Classic
Certified Medical Health Physicist

Answer posted on 24 January 2007. 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.