The picture is worth a thousand words.
D002648:Child; D000013:Congenital Abnormalities / Q000175:diagnosis; D005314:Embryonic and Fetal Development; D005260:Female; D006801:Humans; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D014463:Ultrasonography / Q000009:adverse effects