[The radiation effects of low doses of irradiation on human embryos and fetuses].

Data about the biological effect of irradiation at "small" doses on prenatal development of man are reviewed. The effect of irradiation is observed either immediately after it or in progeny, as consequences of radiation damage to the embryo or fetus. Human embryos and fetuses are most sensitive to ionizing irradiation during the periods of the maximal proliferative activity and differentiation of cells. The concept is formulated that any dose of irradiation, however small, can inflict damage to the embryo or fetus. Problems and perspectives for studies in this field are discussed.