What factors should one consider concerning the risk to the fetus from a CT of the maternal chest or abdomen?

CT should be avoided in pregnant patients whenever possible. One should consider whether an alternative examination will render the diagnosis without ionizing radiation (e.g., MRI, US, V/Q).
However, CT can be valuable, and one should not hesitate to perform a potentially lifesaving examination.
If the mother dies, so does the fetus; if the mother goes into shock, abruptio placentae could occur.