Potential novel biomarkers for gestational diabetes mellitus in first and early second trimesters: A comprehensive review

Gestational diabetes mellitus (GDM) is one of the commonly encountered medical disorders of pregnancy affecting women of childbearing age globally at an alarming rate and causing significant perinatal morbidity and adverse fetal outcomes. The intricate interchanges between genetic susceptibility, metabolic changes and environmental factors contribute to the altered β-cell function, insulin sensitivity and glucose metabolism leading to hyperglycaemia in pregnancy. However, the precise etiology of GDM remains incompletely understood. There is a compelling need for the identification of GDM in at-risk pregnant females at an early stage to improve maternal and fetal outcomes. Ongoing research has revealed numerous biomarkers that can be both predictive and diagnostic for GDM. This review aims to explore the various biomarkers that have increasing evidence for their use as predictors of GDM in the first and early second trimesters. The sensitivity, specificity, accuracy, and predictive power of these biomarkers have been compared to identify the ideal candidate(s), despite the effect of confounding factors. Throughout this review, research gaps were highlighted and future research directions were suggested to accurately diagnose GDM through a panel of efficacious biomarkers well before the disease manifests in later pregnancy.