DIAGNOSTIC ACCURACY OF FASTING BLOOD GLUCOSE LEVEL VS GLUCOSE CHALLENGE TEST IN DIAGNOSING GESTATIONAL DIABETES

Abstract

Objective: The objective of this study is to determine the diagnostic accuracy of fasting blood sugar level and glucose challenge test for screening of gestational diabetes mellitus, taking oral glucose tolerance test (OGTT) as gold standard.

Design: This cross sectional study was carried out in Department of Obstetrics and Gynaecology,OPD of Unit-I, Lahore General Hospital, Lahore for a duration of six months from 1-1-2016 to30-6-2016 . The non-probability purposive sampling technique was used in this study. Women were asked to come on next day early in morning before breakfast with 12 hours fast. The fasting blood sample was obtained. Then women underwent 50 g non-fasting GCT(Glucose challenge ) test on the same day. In both tests, reports were assessed and noted. The patients were labeled as positive or negative for GDM (Gestational Diabetes Mellitus). Then females received 75 g OGTT(Oral glucose tolerance test) one week later on next visit and gestational diabetes was confirmed by OGTT. Reports of gold standard were compared with diagnostic tests.

Results: In our study the sensitivity of FBS was 96.77% with specificity of 98.36%, PPV was 98.59%, NPV was 96.26% and diagnostic accuracy was 97.5% taking GTT as gold standard.-96+30. In this study the sensitivity of GCT was 97.7% with specificity of 98.36%, PPV was 98.6%, NPV was 97.3% and diagnostic accuracy was 98% taking GTT as gold standard.

Conclusion: This study results concluded that Fasting Blood Sugar is a highly accurate test, as is the glucose challenge test for screening of Gestational diabetes mellitus and can be done as a routine screening test as it is easy, one step and cost effective.