Journal of Ultrasound in Medicine, Vol 7, Issue 4 183-187, Copyright © 1988 by American Institute of Ultrasound in Medicine
Factors affecting prenatal sonographic estimation of weight in extremely low birthweight infants
R. R. Townsend, R. A. Filly, P. W. Callen and R. K. Laros
Department of Radiology, University of California, School of Medicine, San Francisco 94143.
Because critical management decisions are based on sonographic estimation
of fetal weight in fetuses less than 1000 g, we sought to evaluate the
accuracy of birthweight prediction in this range and to identify factors
affecting this accuracy. Fetal weight was estimated using several published
methods in 53 fetuses with birthweights less than 1000 g. Standard
deviations greater than 12.3% indicate more random error in the sonographic
weight prediction than has been reported in higher weight groups. No
statistically significant differences were found between patient groups
with decreased, normal, or increased amniotic fluid volume or portable
examination. There was a trend toward lower mean deviation (2.9 vs 6.0%)
and standard deviation (8.9 vs. 15.0%) in studies with scan quality judged
"good" compared with "poor" based on ability to visualize anatomic
landmarks.
