MANAGING THE PATIENT NOT KNOWN TO BE PREGNANT AT THE TIME OF EXPOSURE

When a woman is discovered to be pregnant after having undergone an ionizing radiologic procedure, counseling should be conducted to give her an objective assessment of and perspective of risk. In the vast majority of circumstances potential risks are very small and, on a scale with normally accepted risks of pregnancy, below the threshold for serious concern. Counseling statements such as, “there is a small chance your child will develop cancer” are honest but unnecessarily alarming because they are void of any indication of the likelihood the child will be healthy. Less alarming and more complete counseling might be, “your child will have nearly the same chances of living a healthy life as any other child under similar medical circumstances because the actual risk that your child might develop cancer is very small.” If a quantitative evaluation is requested, then it might be explained that compared to any other child in similar medical circumstances the chances of being healthy are about or better than 99% of the chances that others have. (Note: this does not mean that the chances of being healthy are better than 99% since, for example, the risk of non-radiation related malformation is 3% or higher.) Before meaningful risk assessment can take place, certain information must be gathered. No assessment of risk to a conceptus can be reasonably made without knowing 1) the age of the conceptus or fetus at the time of the examination; and 2) a reasonable estimate of the absorbed dose to the conceptus. In the scenario where the pregnancy is discovered after the X-ray examination is performed, the woman is frequently in an early stage of pregnancy. (One exception to this situation is the adolescent who might not accurately recall her menstrual history, and in whom pregnancy may first be detected after imaging.) Obtaining information about time of conception is important because risk is dependent on gestational age.