Journal of Ultrasound in Medicine, Vol 2, Issue 3 113-116, Copyright © 1983 by American Institute of Ultrasound in Medicine
Estimation of volume and weight of the perinate: relationship to morphometric measurement by ultrasonography
T. R. Thompson and F. A. Manning
A method of determining fetal weight in utero was developed by use of
real-time ultrasonography. A volume model representing trunk and limbs as
cylinders with dimensions related to morphometric parameters was tested on
60 neonates. Head volumes in these 60 neonates were determined from
equations relating head morphometric measures to head volume in 30 neonatal
autopsy specimens. Head density and trunk and limb density were determined
separately on the 60 neonates by study of the variation in overall density
with body proportions. From these density and volume values, total body
mass was estimated. The deviation of neonatal weight estimates from actual
weights at three days postpartum was +/- 4.1 per cent (1 SD). The validity
of this method for fetal weight determination was tested by in utero
ultrasonographic measurement of 31 fetuses before delivery by cesarean
section. The deviation of the weight estimate from the actual weight at
three days postpartum was +/- 8.1 per cent (1 SD), or +/- 7.4 per cent
(absolute mean error).
