The amniotic flop--a new ultrasonographic sign.
D000033:Abortion, Threatened / Q000175:diagnosis; D000328:Adult; D000650:Amnion; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014463:Ultrasonography