title: Fetal nasal bone length during the second trimester of pregnancy in a Turkish population.
abstract: OBJECTIVE
  To determine the distribution of fetal nasal bone length (NBL) according to gestational age during the second trimester of pregnancy in a Turkish population.
  
  
  METHODS
  Fetal NBL and other routine biometric measurements were evaluated retrospectively in 2327 fetuses between 15 and 24 weeks of gestation. The measurements were obtained via transabdominal ultrasound. The distribution of fetal NBL between 15 and 24 weeks of gestation was established, and percentiles were calculated. Relationships between fetal NBL and other parameters were assessed using regression analysis.
  
  
  RESULTS
  Mean (±standard deviation) fetal NBL ranged from 2.95±0.52 at 15 weeks of gestation to 6.26±0.77mm at 24 weeks of gestation. The fifth percentile for fetal NBL was 2.1mm at 15 weeks of gestation and 5.0mm at 24 weeks of gestation. A significant positive correlation was noted between fetal NBL and gestational age (NBL=gestational age×0.37-2.55; R(2)=0.59; p<0.01) and between fetal NBL and biparietal diameter (BPD) (NBL=BPD×0.11-0.33; R(2)=0.61; p<0.01).
  
  
  CONCLUSIONS
  Fetal NBL is less in Turkish subjects compared with non-Turkish subjects.
authors.affiliation: Medeniyet University Goztepe Education and Research Hospital, Istanbul, Turkey.
authors.forename: G
authors.initials: G
authors.lastname: Goynumer
authors.affiliation: Zeynep Kamil Gynaecologic and Paediatric Training and Research Hospital Department of Perinatology, Istanbul, Turkey. Electronic address: drresular@hotmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Arisoy
authors.affiliation: International Hospital, Istanbul, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Yayla
authors.affiliation: Zeynep Kamil Gynaecologic and Paediatric Training and Research Hospital Department of Perinatology, Istanbul, Turkey.
authors.forename: E
authors.initials: E
authors.lastname: Erdogdu
authors.affiliation: International Hospital, Istanbul, Turkey.
authors.forename: N
authors.initials: N
authors.lastname: Ergin
mesh_terms: D000328:Adult; D005006:Ethnicity; D005260:Female; D005865:Gestational Age; D006801:Humans; D009295:Nasal Bone / Q000000981:diagnostic imaging* / Q000196:embryology; D010296:Parietal Lobe / Q000196:embryology; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012016:Reference Values; D012189:Retrospective Studies; D014421:Turkey; D016216:Ultrasonography, Prenatal
keywords: Fetal nasal bone; Nomogram; Turkish population