Our study named Integrated Continuous glucose monitoring glycemic cHAracterization during Pregnancy in comparison with oral glucose tolerance test (I-CHAP) aims to establish much needed preliminary evidence in our Asian population to show the capabilities of CGM use and its wealth of data for GDM diagnosis. This study aims to test the following aims and hypotheses in a single-armed intervention pilot trial study of pregnant women undergoing the oral glucose tolerance test: Aim 1. To characterize CGM glucose values with the 3-point blood glucose measured during the OGTT procedure. The investigators hypothesize that the CGM glucose values at single time points while fasted, and after the 75-g glucose load will be positively correlated with 3-timepoint blood glucose values captured during the OGTT. Aim 2. To correlate the CGM glucose excursions and CGM-derived metrics (glycaemic variability and glycaemic control) with maternal-fetal outcomes and treatment outcomes. The investigators hypothesize that higher AUC, glycemic variability and poorer glycaemic control will better distinguish maternal-fetal outcomes and treatment outcomes, compared to the OGTT. Aim 3. To describe the acceptability of using the Dexcom G6 CGM as a diagnostic tool instead of the OGTT. The investigators hypothesize that a higher proportion of participants will report CGM to be more acceptable than the OGTT for GDM diagnosis.