Answer to Question #61 Submitted to "Ask the Experts"

Q

Does radiation cause mutations in a fetus?

A

At high radiation doses (much greater than 10 rad), mutations (defined as damage to cellular DNA), can occur in cells of the embryo or fetus. As a consequence, developmental abnormalities or cancer may develop. Such occurrences are unusual (for instance in a pregnant cancer patient given radiation treatments). At low doses (less than 10 rad) that are encountered in almost all medical x-ray and nuclear medicine procedures, the probability of inducing mutations in cells in the developing embryo or fetus is so small that risks of developmental abnormalities from radiation exposure are insignificant. There is some evidence that even the small doses used in diagnostic x-ray procedures may increase the risk of leukemia and other childhood cancers. However a causal link between diagnostic radiation exposure of the embryo/fetus and childhood cancer has not been established. Although diagnostic x-ray and nuclear medicine procedures pose little, if any, risk to the embryo/fetus, it is generally recommended that diagnostic radiation tests be postponed during pregnancy if possible to avoid any unnecessary risk, particularly if the examination can be safely postponed.

Kenneth L. Mossman, PhD