title: Sister chromatid exchanges and diagnostic ultrasound.
mesh_terms: D003434:Crossing Over, Genetic; D005260:Female; D005333:Fetus / Q000033:anatomy & histology; D006801:Humans; D011247:Pregnancy; D012854:Sister Chromatid Exchange; D014465:Ultrasonics / Q000009:adverse effects; D014463:Ultrasonography