With the progress of radiology, the use of radiological methods during pregnancy has also increased, especially computed tomography, a method that uses ionizing radiation. At the same time, awareness, concern, and misconceptions among the public and health professionals about the potential risks of exposure to ionizing radiation for the mother and fetus have also increased. It is necessary to weigh the risk of exposure of mother and child to ionizing radiation in order to establish an accurate diagnosis, which can be life-threatening. Radiation adverse effects can be deterministic and stochastic. Deterministic effects occur when a certain number of cells is damaged, with a precisely defined dose threshold before damage occurs. Below a dose of 100 mGy there is no expected deterministic effect of practical significance. Stochastic effects of ionizing radiation occurs when there is damage to individual cells and can result with carcinogenesis. Fetal doses of radiation up to 1 mGy—used in most radiological examinations of the area below the knee and over the diaphragm—are considered admissible, with a risk of carcinogenesis for child less than one in 10,000. With higher doses (e.g. fetal doses of 20-50 mGy received during a CT of pelvic region), the risk of carcinogenesis grows by about factor of 2, but it remains low in absolute terms (less than one in 250). All radiological institutions should have a written instructions for the screening and treatment of pregnant women. Controlled studies on the use of low-osmolality iodine contrast agents during pregnancy in women do not exist, while animal studies in vivo do not show mutagenic and teratogenic effects, therefore the use of these contrast agents during pregnancy is recommended only if clinically important diagnostic information could not be obtained without them. If it is necessary to scan a pregnant woman with a method that uses ionizing radiation, it is necessary to weigh the risks for the mother and child, to reduce the radiation dose by adapting the method, and after the scan to ensure consultation with a physicist, gynecologist and radiologist.