Evaluation of post challenge glucose estimation for diagnosis of gestational diabetes mellitus (W.H.O. - criteria 1999)

Abstract

Predictive Value (NPV) of 75g Oral Glucose Tolerance Test (OGTT) i.e. WHO criteria 1999 with 100g OGTT of National Diabetes Data Group (NDDG criteria). Study Design: Comparative cross sectional. Material & Methods:The study was conducted at Department of Chemical Pathology & Endocrinology, Armed Forces Institute of Pathology (AFIP), Rawalpindi. Duration of study: 1st January 2004 to 31st August 2004. Sample size: Approx one hundred pregnant ladies between 24 to 28 gestational weeks. Sampling technique: Non-probability convenience. Data collection procedure: Patients consent for participation in the study was taken with explanation of test procedure. Patient`s characteristics such as age, obesity, family history of diabetes, pregnancy induced hypertension, previous bad obstetric history (of still birth, macrosomia, recurrence abortion) was recorded on a predesigned proforma. Patients were first called for 75g OGTT and then after a gap of 1-2 days for OGTT 100g. Both tests were performed according to standard protocols. Results: OGTT 75g was found to have 87.5% sensitivity, 97.8% specificity, and 77.7% positive predictive value and 98.8% negative predictive value, when compared with 100g OGTT.