Gestational Diabetes In Women With Normal OGTT: Emerging Evidence And Diagnostic Debates: A Review Article

Abstract

Background: Gestational diabetes mellitus (GDM) is traditionally diagnosed using oral glucose tolerance testing (OGTT), yet growing evidence suggests that a subset of pregnant women exhibit adverse metabolic, obstetric, and neonatal outcomes despite having OGTT values within current “normal” diagnostic thresholds. These observations have raised concerns that the existing criteria may fail to capture milder dysglycemia, postprandial hyperglycemia, or glycemic variability that still confer clinically relevant risk.​​

Aim of work: This review aims to synthesize emerging data on gestational diabetes–related phenotypes in women with normal OGTT results, highlight proposed alternative biomarkers and diagnostic strategies, and critically discuss ongoing debates regarding threshold selection and underdiagnosis.​

Methods: A narrative literature review will be conducted using PubMed, Scopus, and Google Scholar to identify clinical trials, observational studies, and consensus statements published from 2010 to 2025 that evaluate maternal and neonatal outcomes, glycemic markers, and diagnostic performance in pregnant women with normal OGTT but suspected dysglycemia. Search terms will include “gestational diabetes,” “normal OGTT,” “borderline GDM,” “mild hyperglycemia in pregnancy,” “continuous glucose monitoring,” and “diagnostic criteria.”​​

Results: Preliminary evidence indicates that women with OGTT values in the high-normal range or with abnormal postprandial profiles on continuous glucose monitoring may have increased risks of hypertensive disorders, large-for-gestational-age infants, cesarean delivery, and metabolic complications compared with women with lower glycemic indices. Studies evaluating HbA1c, fasting plasma glucose, one-step versus two-step screening, and CGM-based metrics suggest that current OGTT-based thresholds may underestimate risk in certain subgroups, although findings remain heterogeneous and methodologically variable.​ Conclusion: Emerging data support the hypothesis that clinically important gestational dysglycemia can occur even when OGTT results meet current diagnostic standards, prompting calls to re-examine cut-off points, integrate complementary biomarkers, and adopt more individualized risk stratification. However, any revision of criteria must carefully balance earlier detection against the potential for overdiagnosis, overtreatment, and unnecessary healthcare burden, underscoring the need for robust prospective studies and consensus-driven guidelines.​