title: Distal femoral epiphyses ossification center diameter and third trimester gestational age in Iranian population.
abstract: OBJECTIVE
  The epiphyses ossification centers appear late in gestation, when traditional biometric measurements are the least accurate, and they can be useful in determining third trimesters gestational age. To evaluate fetal distal femoral epiphysis (DFE) size in various ages of gestation and establish a reference chart for Iranian population.
  
  
  METHODS
  DFE diameter was measured in 1300 normal singleton pregnancies, between 28 and 40 weeks. Mean diameter in each week of gestation was evaluated.
  
  
  RESULTS
  The DFE is not visualized in 28 weeks' gestation. It appeared in a small proportion of the fetuses (5%) as early as the 29th week. DFE was detectable by ultrasonography increased dramatically to 56% at 33 weeks' reaching 94% at 36 weeks and 100% at 37 weeks gestation.
  
  
  CONCLUSIONS
  Ultrasonographic visualization of the distal femoral epiphyses ossification center is a useful marker of fetal third trimesters gestational age.
authors: Department of Radiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. swt_f@yahoo.com
authors: Shirin
authors: S
authors: Birang
authors: Department of Radiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Ali Akbar
authors: AA
authors: Ameri
authors: Department of Obstetrics and Gynecology, Tehran University of Medical Sciences, Tehran, Iran.
authors: Zahra
authors: Z
authors: Najmi
mesh_terms: D000328:Adult; D000365:Age Determination by Skeleton / Q000379:methods*; D004838:Epiphyses / Q000000981:diagnostic imaging* / Q000196:embryology* / Q000254:growth & development; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000196:embryology* / Q000254:growth & development; D005865:Gestational Age; D006801:Humans; D007492:Iran; D008297:Male; D010012:Osteogenesis / Q000502:physiology*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D014463:Ultrasonography