title: Cross-sectional study of fetal long-bone length in an Iranian population at 17-25 weeks of gestation.
abstract: OBJECTIVE
  To construct improved reference charts for fetal long bones in an Iranian setting and to compare them with previous studies.
  
  
  METHODS
  The present prospective cross-sectional study included singleton fetuses assessed by ultrasonography at 17-25 weeks of gestation at the Comprehensive Medical Genetics Center, Shahid Soltani, Shiraz, Iran between May 1, 2012, and February 28, 2014. Exclusion criteria included conditions that could affect fetal growth. Fetal long bones (femur, humerus, tibia, fibula, ulna, and radius) were measured with ultrasonography and biometric charts were produced. Regression models were fitted to estimate bone lengths. The models produced were compared with those from previous studies in other populations.
  
  
  RESULTS
  There were 660 singleton fetuses included and 660 femur, 633 humerus, 512 tibia, 498 fibula, 505 ulna, and 498 radius biometric measurements were recorded. The models generated to predict the length of the tibia, fibula, ulna, and radius from the length of the femur and humerus demonstrated a high goodness of fit when the predicted lengths were plotted against the actual lengths. Comparisons of mean lengths with previous studies suggested that long-bone length was affected by maternal ethnicity.
  
  
  CONCLUSIONS
  The equations generated could be used to predict long-bone length in an Iranian population and ethnicity should be considered when using fetal long-bone length as a prenatal diagnostic tool.
authors.affiliation: Maternal-Fetal Medicine Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Kasraeian
authors.affiliation: Department of Biostatistics, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Hadi Raeisi
authors.initials: HR
authors.lastname: Shahraki
authors.affiliation: Maternal-Fetal Medicine Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Asadi
authors.affiliation: Maternal-Fetal Medicine Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Homeira
authors.initials: H
authors.lastname: Vafaei
authors.affiliation: Maternal-Fetal Medicine Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Safoura
authors.initials: S
authors.lastname: Sameni
mesh_terms: D001846:Bone Development / Q000502:physiology; D003430:Cross-Sectional Studies; D005269:Femur / Q000033:anatomy & histology / Q000196:embryology*; D005360:Fibula / Q000033:anatomy & histology / Q000196:embryology*; D005865:Gestational Age; D006801:Humans; D006811:Humerus / Q000033:anatomy & histology / Q000196:embryology*; D007492:Iran; D011446:Prospective Studies; D011884:Radius / Q000033:anatomy & histology / Q000196:embryology*; D012016:Reference Values; D014457:Ulna / Q000033:anatomy & histology / Q000196:embryology*; D016216:Ultrasonography, Prenatal
keywords: Femur; Fetal long bones; Fibula; Humerus; Iran; Radius; Tibia; Ulna