Absence of nasal bone and detection of trisomy 21.
De Biasio
Pierangela
P
Venturini
Pier Luigi
PL
D004314:Down Syndrome / Q000175:diagnosis*; D005260:Female; D006801:Humans; D009295:Nasal Bone / Q000002:abnormalities / Q000000981:diagnostic imaging*; D011247:Pregnancy; D015203:Reproducibility of Results; D016216:Ultrasonography, Prenatal