GESTATIONAL DIABETES;

Accuracy of glucose challenge test (GCT) for screening.

Abstract

Objective: To determine the Accuracy of GCT for screening of gestational diabetes in high risk population comparing oral
Glucose Tolerance Test (GTT) as gold standard. Main outcome measures: Accuracy of GCT. Study design: Cross-sectional study.
Setting: The study was conducted in outpatient department of Punjab Medical College and affiliated hospitals, Faisalabad. Subjects: 207
patients. Methods: High risk women from outpatient department were recruited on the basis of inclusion and exclusion criteria after
explaining pros and cons of procedure. These women were subjected to GCT & GTT. GTT was taken as gold standard test and results of
GCT were compared with it. Main outcome measures recorded and results obtained. Results: Out of 207 women, GCT truly diagnosed 24
women as having diabetes (true positive) & 175 women were found to have normal glucose metabolism (true negative). GCT failed to
diagnose 5 diabetic women (false negative) & wrongly diagnosed 3 normal women as diabetics (false positive) against gold standard
GTT. So GCT has diagnosed Gestational diabetes mellitus with the sensitivity of 82.7%, specificity of 98.3%, positive predictive value of
88.8%, and negative predictive value of 97.2% and accuracy of 96.1%. Conclusions: GCT is a simple, easy, convenient and sensitive test
that has no limitation for time or prior fasting for gestational diabetes screening.