Journal of Ultrasound in Medicine, Vol 3, Issue 1 1-3, Copyright © 1984 by American Institute of Ultrasound in Medicine
Relation of fetal femur length to neonatal crown-heel length
F. P. Hadlock, R. L. Deter, E. Roecker, R. B. Harrist and S. K. Park
Sonographically measured femur lengths in 102 fetuses were compared with
neonatal crown-heel lengths within 72 hours of delivery. The optimal model
for describing crown-heel length as a function of femur length was a linear
model, with a coefficient of determination (r2) of 66 per cent; the
standard deviation in predicting crown-heel length from femur length was
2.4 cm. These data were compared with autopsy data from the literature,
which showed an even stronger correlation between femur length and
crown-heel length. Because of the strong correlation between these two
dimensions, the femur length should prove useful in the detection of
intrauterine growth retardation when crown-heel length is compromised. It
should also be useful as a variable in the prediction of fetal weight in
utero, since crown-heel lengths at the extremes of normal can significantly
affect in utero weight estimates using ultrasound.
