ICRP Publication 90: Biological Effects after Prenatal Irradiation (Embryo and Fetus)

In its 1990 recommendations, the ICRP considered the radiation risks after radiation exposures during prenatal development. This report critically reviews new experimental animal data on biological effects and evaluations of human studies after prenatal radiation published since then.

Thus, the report discusses radiation effects after exposure during preimplantation and developmental effects after irradiation during organogenesis and fetogenesis. The etiology of long-term effects during brain developments is discussed, as well as evidence from studies in man on the effects of in utero radiation exposure on neurological and mental processes. Assessments through animal studies of carcinogenic risk from in utero radiation are treated, and the epidemiology of childhood cancer is discussed; from this information the carcinogenic risk to man from in utero radiation is assessed. Open questions and needs for future research are elaborated.

The report reiterates that the mammalian embryo and fetus are very radiosensitive during prenatal development. The nature and sensitivity of induced biological effects depend upon dose and developmental stage at irradiation. The various effects, as studied in experimental systems and in man, are discussed in detail. It is concluded that the findings in the report strengthen and supplement the recommendations of the ICRP.