title: Prospective experience with integrated prenatal screening and first trimester combined screening for trisomy 21 in a large Canadian urban center.
mesh_terms: D002170:Canada / Q000453:epidemiology; D004314:Down Syndrome / Q000196:embryology / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000379:methods* / Q000706:statistics & numerical data; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011295:Prenatal Care; D014505:Urban Population / Q000706:statistics & numerical data