title: Optimal standards for fetal biometry: to each measurement its fitting model.
abstract: OBJECTIVE
  To determine the best mathematical model to construct charts of fetal abdominal circumference (AC) and femur length (FL).
  
  
  METHODS
  Ultrasound measurements were made on 1,336 normal fetuses in one center. Four mathematical models were compared (a linear-quadratic model, a linear-cubic model, the Rossavik model and a new two-phase model, which has been found to best fit fetal head data).
  
  
  RESULTS
  The best fitting of AC and FL data was obtained with the linear-quadratic model without separate computing for gender. Centile charts have been computed.
  
  
  CONCLUSIONS
  Fetal growth of AC and FL is much simpler than that of the head. Therefore, a unique mathematical model should not be used to fit all measurements.
authors.affiliation: Unité Propre de Recherche 2147, Centre National de la Recherche Scientifique, Paris, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Pineau
authors.forename: Olivier
authors.initials: O
authors.lastname: Thiebaugeorges
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Guihard-Costa
mesh_terms: D000005:Abdomen / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D001699:Biometry; D005260:Female; D005269:Femur / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D047109:Fetal Development; D005333:Fetus / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D016216:Ultrasonography, Prenatal