Requirements for radiation protection of pregnant women in planned and emergency exposure situations

Radiation exposure of pregnant women can not only increase the likelihood of stochastic effects for both the mother and the unborn child, but lead to the development of various birth defects as well. Revision of Rospotrebnadzor's regulations on radiation protection from medical and emergency exposure requires updating requirements for radiation protection of pregnant women. They should be based on modern scientific epidemiological and radiobiological data. The aim of this study was to develop requirements for radiation protection for pregnant women in various exposure situations. Materials and Methods: This study was based on a systematic review of Russian and international regulatory documents governing radiation protection for pregnant women during medical and emergency exposure, as well as epidemiological studies. Results and Discussion: The results of the analysis indicated that exposure of the fetus or embryo to ionizing radiation is associated with less than 2 % of congenital malformations identified in newborns. A threshold value of 100 mGy of absorbed dose in the fetus (embryo) is accepted as the threshold below which it is impossible to reliably determine deterministic effects associated with exposure to ionizing radiation. To ensure a conservative approach to radiation protection of pregnant women in Russian practice, it has been proposed to establish a dose constraint for pregnant women of 50 mGy of absorbed dose in the fetus (embryo) for the period from the moment of detection of pregnancy until delivery for situations involving routine medical care. Conclusion: This will prevent the development of malformations in the child and minimize the likelihood of radiation-induced cancer after birth. A value of 500 mGy of absorbed dose in the fetus (embryo) has been proposed as the criterion for radiation accidents. This approach will be implemented in the new edition of the Norms of Radiation Safety and the Basic Sanitary Rules for Radiation Safety.