title: Is there an optimal gestation for ultrasound examination of fetal nasal bone in the first trimester?
authors.forename: Pui Wah
authors.initials: PW
authors.lastname: Hui
authors.forename: Chin Peng
authors.initials: CP
authors.lastname: Lee
authors.forename: Wing Cheong
authors.initials: WC
authors.lastname: Leung
authors.forename: Mary Hoi Yin
authors.initials: MH
authors.lastname: Tang
mesh_terms: D000028:Abortion, Induced; D000328:Adult; D003937:Diagnosis, Differential; D004314:Down Syndrome / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D009295:Nasal Bone / Q000000981:diagnostic imaging* / Q000196:embryology*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D016216:Ultrasonography, Prenatal