title: Down's syndrome: sex difference in relation to maternal age.
mesh_terms: D004314:Down Syndrome / Q000209:etiology* / Q000235:genetics; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D012723:Sex; D012737:Sex Factors