Answer to Question #1337 Submitted to "Ask the Experts"

Q

I conceived my child on 27 September of this year. I went to the dentist on 2 October. They did bite wing x rays on my teeth. I then had a CT scan on my sinus on 5 October. The technicians asked if there was a possibility I could be pregnant, and I said YES, there is, that my husband and I have been trying, but I wouldn't know until I missed my cycle that would begin on the 13^th. They said, well even if you are pregnant, you'll be okay. They put a lead apron over my back, and I was lying on my stomach and they proceeded. Well, needless to say—I found out I WAS INDEED PREGNANT, but am now TERRIFIED that my baby could be retarded or develop cancer or something will go wrong. I want some medical expert opinion on this.

A

I understand your concern and I will try to explain why your anxiety and concern is not warranted in your present situation. When you receive a diagnostic x ray study of your head, teeth, chest, arms, or legs at a qualified facility, the exposure by the x rays is not to your embryo. The "scatter" that might reach the embryo would be extremely small and would not represent an increased risk for birth defects or miscarriage to your embryo. The most important characteristic of x rays that concerns us is the dose.

You may not know that we ourselves are radioactive and we are exposed to many sources of natural radiation which we cannot avoid. Your developing embryo did not receive a dose that would result in any measurable increased reproductive risk. If you are healthy and young and have no reproductive problems or family history of reproductive problems your risk for birth defects is 3% and for miscarriage, 15%. Neither you nor I can change that risk which all mothers have when they begin a pregnancy. Good luck with your pregnancy.

Robert L. Brent, MD, PhD