Current approach to early gestational diabetes mellitus: A clinical update

Aims: Early gestational diabetes (eGDM) is defined as hyperglycemia diagnosed in early pregnancy (<20 weeks) which is not overt or pre-existing diabetes. This review summarizes our current understanding of eGDM and identifies future research gaps. Methods: A literature search was conducted using PubMed, Google Scholar and Scopus databases, focusing on the diagnostic pathways, glycemic trajectories, impact of treatment on pregnancy outcomes, and evolving precision medicine approaches in eGDM. Results: Currently, there is no consensus on the diagnostic criteria and screening approach for eGDM. The WHO 2013 criteria, which adopt IADPSG thresholds for diagnosis throughout the pregnancy are most commonly employed. The pathophysiology involves interplay of defective beta-cell function and insulin resistance, however, early-onset gestational insulin resistance is a distinct feature. Nearly 30-50 % of women with eGDM regress to normoglycemia at 24-28 weeks of gestation. Observational studies report that eGDM is associated with increased risk of adverse pregnancy outcomes despite treatment. A recent multicenter randomized controlled trial (TOBOGM) found that immediate treatment of eGDM, compared to deferred or no treatment, is associated with modest neonatal benefits, chiefly driven by the reduction in risk of neonatal respiratory distress. Precision medicine approaches are on horizon in the management of eGDM. Differential enactment pathways have been proposed, wherein women with OGTT results in lower glycemic band are kept under close follow-up, whereas those in the higher glycemic band are treated more aggressively. Conclusion: eGDM is a distinct medical condition, associated with increased risk of adverse pregnancy outcomes, and modest neonatal benefits upon immediate treatment.