[Frequency of prenatal x-ray examination and radiation risks in Japan (author's transl)].
D005260:Female; D005333:Fetus / Q000528:radiation effects*; D006801:Humans; D007564:Japan; D011247:Pregnancy; D011829:Radiation Dosage; D011839:Radiation, Ionizing; D012306:Risk; D014965:X-Rays