Regarding: Fasting Glucose for the Diagnosis of Gestational Diabetes Mellitus (GDM) during the COVID-19 Pandemic

Abstract

First trimester fasting plasma glucose is nowadays routinely measured during early pregnancy for overt diabetes screening, using a threshold of 126mg/dl. Various international guidelines proposed different fasting plasma glucose threshold levels for the diagnosis of GDM along with the 2 step OGTT. Gonzalez et al. reported that using First trimester fasting plasma glucose value of 100 mg/dl for diagnosis of GDM, 79.5% pregnant women were undiagnosed. In non-GDM group, 3.2% normal glucose tolerance women were identified with first trimester fasting plasma glucose of greater than 100 mg/dl. Gonzalez et al concluded that FPG is not a good test for diagnosis of GDM [1]. Studies reported that mean first trimester fasting plasma glucose of range 82.4 mg/dl to 89.74 mg/dl were significantly associated in predicting the risk of GDM at 24-28 weeks of gestation and adverse pregnancy outcomes [3-8]. Despite the limitations of observational retrospective study design and different ethnicity, these studies could help to shed some lights to our knowledge that have not been previously considered. Few prospective studies have reported that a mean first trimester fasting plasma glucose of 92.93 mg/dl to 94.6 mg/dl were significantly associated in predicting the risk of later development of GDM. Keeping innmind that there is a physiological drop in the fasting plasma glucose (FPG), FPG threhold of 82-89 mg/dl (<92mg/dl) is statistically significant in predicting the risk of later development of GDM in pregnant women. First trimester fasting plasma glucose can be used as a screening marker in predicting the risk of GDM, although it cannot replace the current gold standard OGTT. Due to the limited number of studies available in India, future multi-centric studies were needed to generalize the results, to validate and improve the diagnosing criteria of GDM.