Optimal standards for fetal biometry: to each measurement its fitting model.
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.
Pineau
Jean-Claude
JC
Unité Propre de Recherche 2147, Centre National de la Recherche Scientifique, Paris, France.
Thiebaugeorges
Olivier
O
Guihard-Costa
Anne-Marie
AM
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