title: Effects of prenatal exposure to ionizing radiation.
abstract: Prenatal exposure to ionizing radiation induces some effects that are seen at birth and others that cannot be detected until later in life. Data from A-bomb survivors in Hiroshima and Nagasaki show a diminished number of births after exposure under 4 wk of gestational age. Although a wide array of congenital malformations has been found in animal experimentation after such exposure to x rays, in humans only small head size (exposure at 4-17 wk) and mental retardation (exposure primarily at 8-15 wk) have been observed. In Hiroshima, small head size occurred after doses of 0.10-0.19 Gy or more, and an excess of mental retardation at 0.2-0.4 Gy or more. Intelligence test scores were reduced among A-bomb survivors exposed at 8-15 wk of gestational age by 21-29 IQ points per Gy. Other effects of in-utero exposure to atomic radiation include long-lasting complex chromosome abnormalities.
authors.affiliation: Clinical Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892.
authors.forename: R W
authors.initials: RW
authors.lastname: Miller
mesh_terms: D000016:Abnormalities, Radiation-Induced / Q000473:pathology; D002386:Cataract / Q000209:etiology; D005260:Female; D005298:Fertility / Q000528:radiation effects; D005333:Fetus / Q000528:radiation effects*; D006801:Humans; D008607:Intellectual Disability / Q000209:etiology; D009381:Neoplasms, Radiation-Induced; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects