Before meaningful risk assessment can take place, certain information should be gathered. No reasonable assessment of risk to a conceptus can be 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..)