Answer to Question #1811 Submitted to "Ask the Experts"

Q

My two-year-old son had an x ray of his adenoids and I had to hold him while the test was done. I didn't know the damage it might have to my unborn baby. I am 10 weeks pregnant and I am very worried what may have happened to my baby. My husband told me that the baby could be born with birth defects or blind from the radiation. Please help me.

A

First of all, if you were 10 weeks pregnant at the time of the x ray all the major organs have been formed. Secondly the x-ray machine has a cone and filter, therefore the amount of radiation that you received was some small fraction of the exposure that your child was exposed to. Your exposure would even be much less if you wore a lead apron. If you want a definitive answer you could ask the Radiology Department to calculate the estimated exposure that your fetus received. It will be very low. I can't calculate it because I do not have the number of films and the exposure parameters. I do not know where you were standing, etc. However, it would be most unusual if your fetus received an exposure that would result in any effects. The threshold for birth defects is approximately 20,000 mrads and your fetus probably received a only few mrads, an exposure of no consequences. So please don't get upset. Remember that women with a good family history and reproductive history have a background risk of 3% for birth defects and 15% for miscarriage. Neither you or I can change that risk. Good luck. Robert Brent, MD, PhD