Ultrasound in Obstetrics and Gynecology · 2004 · 66 citations · 19 references
At 11-14 weeks of gestation, maxillary length in trisomy 21 fetuses is significantly shorter than in normal fetuses.
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A H BECKETT, M ROWLAND, P TURNER · The Lancet · 1965 · 16.9K citations
K. H. Nicolaides, G.B. Azar, Dominic Byrne et al. · BMJ · 1992 · 1K citations · Full text
Observations on an Ethnic Classification of Idiots
J. Langdon H. Down · Journal of Mental Science · 1867 · 591 citations
Ethnicity, Culture, Social Identity +12