Fetal Length Predicted from Femur Length

The femur is relatively easy to identify and measure on ultrasound. From the femur length it is possible to predict the fetal length.

According to Vintzileos (1984), for fetuses of 23 - 42 weeks gestation:

fetal length in cm =

= 6.18 + (0.59 * (femur length in mm))

According to Ott (1985):

fetal crown-heel length in cm =

= 11.887 + (5.158 * (femur length in cm))

According to Hadlock (1984):

fetal crown heel length in cm =

= 9.50 + (5.41 * (femur length in cm))

To read more or access our algorithms and calculators, please log in or register.