title: Impact of prenatal chromosomal diagnosis in order women on population incidence of severe mental retardation.
mesh_terms: D000328:Adult; D004314:Down Syndrome / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D011296:Prenatal Diagnosis