Ultrasound imaging in pregnancy. ACOG Committee Opinion: Committee on Obstetrics: maternal and fetal medicine. Number 96--August 1991.
D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging*; D016216:Ultrasonography, Prenatal