title: Frequency of prenatal X-ray examination and radiation risks in Japan.
mesh_terms: D005260:Female; D005333:Fetus / Q000528:radiation effects*; D005865:Gestational Age; D006801:Humans; D007564:Japan; D010388:Pelvis / Q000000981:diagnostic imaging; D011247:Pregnancy; D011859:Radiography / Q000009:adverse effects*; D011860:Radiography, Abdominal; D012306:Risk