title: Ethnic variation of fetal nasal bone length between 11-14 weeks' gestation.
abstract: OBJECTIVE
  We sought to compare the fetal nasal bone length (FNBL) between different ethnic groups at 11-14 weeks' gestation.
  
  
  METHODS
  FNBL and the FNBL/CRL ratio were measured in patients undergoing first trimester ultrasound for nuchal translucency (NT) and the ethnicity of the patient was recorded under four categories: non-Hispanic White, non-Hispanic black, Hispanic, and Chinese.
  
  
  RESULTS
  Two hundred and one patients were included in the study. Measurement of the FNBL could not be obtained in nine patients (4.5%) and foetal nasal bone was absent in one fetus. Comparing the four groups, non-Hispanic White, non-Hispanic Black, Hispanic, and Asian, there were no statistical differences in crown-rump length (61 +/- 14 mm; 68.6 +/- 15 mm; 60.2 +/- 14 mm; 62.4 +/- 8.8 mm, respectively) or the NT (1.3 +/- 0.5 mm; 1.25 +/- 0.4 mm; 1.35 +/- 1 mm; 1.4 +/- 0.4 mm, respectively). However, the FNBL (2.9 +/- 0.7 mm; 2.5 +/- 0.6 mm; 2.5 +/- 0.6 mm; 2.2 +/- 0.4 mm, respectively, p < 0.01) and the FNBL/CRL ratio (0.049 +/- 0.01, 0.045 +/- 0.01, 0.043 +/- 0.01, 0.037 +/- 0.01, respectively, p < 0.01) were both statistically different, when comparing between these groups.
  
  
  CONCLUSIONS
  If the FNBL is to be introduced into first-trimester screening, it should be adjusted for ethnicity.
authors.affiliation: Department of Obstetrics and Gynecology, Lutheran Medical Center, Brooklyn, NY, USA.
authors.forename: Fadi
authors.initials: F
authors.lastname: Collado
authors.forename: Allan
authors.initials: A
authors.lastname: Bombard
authors.forename: Vuysan
authors.initials: V
authors.lastname: Li
authors.forename: Kell
authors.initials: K
authors.lastname: Julliard
authors.forename: Leslie
authors.initials: L
authors.lastname: Aptekar
authors.forename: Zeev
authors.initials: Z
authors.lastname: Weiner
mesh_terms: D044466:Asian People; D044383:Black People; D015331:Cohort Studies; D000013:Congenital Abnormalities / Q000175:diagnosis* / Q000196:embryology / Q000208:ethnology; D018568:Crown-Rump Length; D004314:Down Syndrome / Q000175:diagnosis* / Q000196:embryology / Q000208:ethnology; D005260:Female; D005865:Gestational Age; D006630:Hispanic or Latino; D006801:Humans; D009295:Nasal Bone / Q000000981:diagnostic imaging / Q000196:embryology*; D048208:Nuchal Translucency Measurement; D010865:Pilot Projects; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D011446:Prospective Studies; D044465:White People