Antenatal screening.
D000328:Adult; D002877:Chromosomes, Human / Q000032:analysis; D004314:Down Syndrome / Q000175:diagnosis; D005260:Female; D006801:Humans; D008131:London; D008423:Maternal Age; D008875:Middle Aged; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D014463:Ultrasonography; D000509:alpha-Fetoproteins / Q000032:analysis
D000509:alpha-Fetoproteins