Radiation Effects in the Embryo and Fetus

Abstract

The severity of the effects of ionizing radiation on the pre- and post-implantation embryo/fetus is dependent upon the dose, dose rate, and stage of gestation. In the pre-implantation (conceptus) stage, relatively low doses of radiation may result in death; in surviving embryos, malformations are unlikely. During organogenesis, radiation may cause severe organ malformations along with the possibility of fetal death or growth retardation. During the fetal growth stage, radiation may cause permanent growth retardation, mental retardation and microcephaly. Prenatal radiation may also cause radiation-induced carcinogenesis at a rate higher than what is expected in children or adults.