Answer to Question #2639 Submitted to "Ask the Experts"

Q

I had an abdominal diagnostic CT scan this week and, as part of that, swallowed barium and had IV iodine. Assuming the tests come back normal, we have been planning to try to get pregnant in about two weeks. I am 39 years old and have one healthy daughter. Is it a good idea to get pregnant? Will all of the barium/iodine be out of my system? Can it affect a new embryo? My radiologist said there is no problem.

A

Since you had an abdominal CT scan that means that your ovaries were exposed to a dose of radiation of approximately 3 to 5 rad or 30 to 50 mSv. For genetic risks this is a very small exposure. The data from the atomic bomb survivors who received much higher exposures indicates that genetic risks from radiation directly to the ovaries are very small. Studies of cancer survivors from studies performed by the National Cancer Institute also indicate that reproductive risks are barely increased even in women who were treated with chemotherapy and high radiation to the ovaries. This type of exposure would not affect your fertility. The iodine will be out of your system in a short period of time and the thyroid does not begin to concentrate iodine for 8 to 10 weeks after the embryo begins to develop. So you should not be concerned about the future effect of the CT scan.

The barium is not absorbed into your body, so it is of no concern. At 39, you are considered, when pregnant, to be at higher risk for certain reproductive problems and that is why they would suggest that you have amniocentesis or chorionic villous sampling (CVS) to determine whether your fetus would have any problems of which you should be aware. The normal risk for birth defects is 3% and for miscarriage 15%.

Good luck and I wish you well.

Robert L. Brent, MD, PhD