Diagnostic Value of Fasting Plasma Glucose in Screening of Gestational Diabetes Mellitus

Today, although screening tests for Gestational Diabetes Mellitus (GDM) are available, they are time-consuming and expensive; hence perform-ing tests that are cheaper but have higher sensi-tivity and specificity seems necessary. The aim of this study was to determine a cut off point of fasting plasma glucose (FPG) for screening GDM. Materials and Methods: In this clinical trial, 200 pregnant women aged ≥25 years referring to a perinatal clinic were selected. Inclusion criteria re-quired having one of the following risk factors: His-tory of recurrent abortion, GDM, pre-eclampsia, macrosomia, still birth, or diabetes mellitus(DM) in first degree family or pre gestational body mass index ≥25kg/m2. All participants underwent a 50 g glucose challenge test (GCT) between the 24th and 28th gestational week. If 1-hour plasma glu-cose was over 130 mg/dL, a 3-hour 100g oral glu-cose tolerance test (OGTT) was recommended. The diagnosis of GDM was made based on ADA recommendations. Results: Of 200 participants, 65 women had posi-tive GCT, of which 58 (response rate 89%) were referred for 100g OGTT and 20 (10%) were di-agnosed with GDM. The under curve area for FPG of 0.85 and the FPG level of 91.5 mg/dL, showed highest sensitivity -80%, and specificity -92%, respectively in the diagnosis of GDM. Significant difference was observed between the GDM and normal groups for mean age, gravid-ity, parity and BMI (P<0.05). Conclusion: Fasting plasma glucose (FPG) ≥ 91.5 mg/dL has good sensitivity and specificity in the screening of GDM; since this is simpler and cheaper than the 50g GCT, it is recommended as a screening method for the diagnosis of GDM.