Safety of diagnostic ultrasound in obstetrics.
D000022:Abortion, Spontaneous / Q000209:etiology; D000013:Congenital Abnormalities / Q000209:etiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis; D014465:Ultrasonics / Q000009:adverse effects; D014463:Ultrasonography