title: Amniotic fluid alpha-fetoprotein levels and trisomy 21.
mesh_terms: D000653:Amniotic Fluid / Q000032:analysis*; D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012306:Risk; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D000509:alpha-Fetoproteins