One of the essential purpose of prenatal care is the measurement of fetal growth and also estimation of fetal age. Sonography is a valid device with measurement of femoral length , Scapula length , Biparietal diameter and abdominal circumference.

To compare the value of these parameters in assessing fetal age a cross sectional study on 220 singleton pregnancies with the gestational age of 16-40 weeks was designed. Our cases who knew her LMP and had no history of previous disease and also fetal anomaly were assesed based on sonographic scores .

Findings showed that scapular length and biparietal diameters are the best parameters for estimating gestational age. Multivariate regression showed estimation of G.A based on each of the variables alone is better than multivariate estimation.  

        Results suggest that sonography is a valuable device for assessment of fetal growth and biparietal diameter and scapula length seem to be better indices for estimation of gestational age.