Gestational diabetes: fasting capillary glucose as a screening test in a multi-ethnic, high-risk population

Aims In populations at high risk of gestational diabetes mellitus (GDM), screening every pregnant woman by an oral glucose tolerance test (OGTT) is very demanding. The aim of this study was to determine the value of the fasting capillary glucose (FCG) as a screening test for GDM. Methods FCG was measured by a plasma-correlated glucometer in 1465 pregnant women who underwent a one-step diagnostic 75-g OGTT for universal screening of GDM. Results One hundred and ninety-six (13.4%) women had GDM as defined by the criteria of the American Diabetes Association. The area under the receiver operating characteristic curve (AUC) of the FCG was 0.83 (95% confidence interval 0.80-0.86). A FCG threshold of 4.7 mmol/l (at an acceptable sensitivity of 86.0%) independently could rule-out GDM in 731 (49.9%) women, while the FCG could rule-in GDM (100% specificity) in 16 (1.1%) additional women; therefore, approximately half of the women would not need to continue with the cumbersome OGTT. Conclusions Screening using a FCG significantly reduces the number of OGTTs needed for the diagnosis of GDM. Wider assessment, particularly in low-risk populations, would confirm the potential value of the FCG as a screening test for GDM.