Accuracy of Ultrasonic Fetal Abdominal Subcutanous Fat Thickness Measurement in Predicting Intrauterine Growth Restriction (IUGR)

Abstract

Objective To evaluate the sensitivity and specificity of subcutaneous fat thickness in predicting
intrauterine growth restriction (IUGR).
Study design Prospective descriptive study.
Setting Maharaj Nakorn Chiang Mai Hospital, Chiang Mai University.
Subjects Women meeting the inclusion criteria of : (1) singleton pregnancies at 26-37 weeks of
gestation; (2) known accurate gestational age; (3) clinically suspected IUGR.
Methods The patients were sonographically examined at 35-37 weeks of gestation for
subcutaneous fat thickness. Subcutaneous fat thickness was measured in millimeters on the
anterior abdominal wall, at the level of the junction of the umbilical vein and the left portal vein,
using fullscreen magnification. The best cut-off value of subcutaneous fat thickness in
predicting IUGR was determined by a receiver operating characteristic (ROC) curve. The
fetus with asubcutaneous fat thickness less than the cut-off value was antenatally diagnosed
as IUGR. The gold standard for diagnosis of IUGR was defined as low birthweight of less than
the 10th percentile.
Main outcome measures sensitivity, specificity, positive predictive value and negative predictive
value.
Results One hundred and ten pregnancies with suspected IUGR were analyzed. The
prevalence of IUGR among the study group was 22.72%. The best cut-off value of the
subcutaneous fat thickness for prediction of IUGR was 4.5 mm, giving the sensitivity,
specificity, positive predictive value and negative predictive value of 76.0%, 75.3%, 47.5% and
91.4%, respectively.
Conclusion Measurement of subcutaneous fat thickness is a simple technique. It may be used in
predicting nutritional status antenatally as an adjunct with other standard parameters.