title: The U.S. National Reference Preparation for alpha-fetoprotein in mid-pregnancy maternal serum.
mesh_terms: D000757:Anencephaly / Q000097:blood; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012015:Reference Standards; D016136:Spina Bifida Occulta / Q000097:blood; D014481:United States; D000509:alpha-Fetoproteins / Q000032:analysis / Q000592:standards*
chemical_list: D000509:alpha-Fetoproteins