title: Rates of Down syndrome at the upper extreme of maternal age: considerations and recommendations in analysis.
authors.forename: Ernest B
authors.initials: EB
authors.lastname: Hook
mesh_terms: D000328:Adult; D004314:Down Syndrome / Q000196:embryology* / Q000453:epidemiology*; D005260:Female; D006287:Health Planning Guidelines; D006801:Humans; D008423:Maternal Age; D008875:Middle Aged; D011296:Prenatal Diagnosis / Q000706:statistics & numerical data*