title: Screening for Down syndrome.
mesh_terms: D000328:Adult; D000649:Amniocentesis / Q000009:adverse effects; D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D006801:Humans; D008423:Maternal Age; D008875:Middle Aged; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D012307:Risk Factors; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: D000509:alpha-Fetoproteins