Adapted Screening Methods for Gestational Diabetes in Low-Resource Settings-A Narrative Review of Observational Studies

Gestational diabetes mellitus (GDM) affects approximately 14%-17% of pregnancies worldwide, with the vast majority of cases occurring in low-resource settings. There is an ongoing debate concerning the optimal screening and diagnosis of GDM, as the current diagnostic recommendation of performing a universal oral glucose tolerance test (OGTT) for every pregnant woman (WHO, 2013) is resource-intensive and can potentially lead to overdiagnosis. This narrative literature reviews aimed to evaluate the diagnostic sensitivity of alternative, less resource-demanding screening methods that could be appropriately used for low-resource settings.

For this narrative review, observational studies were identified via PubMed. The PRISMA guidelines were used to guide this process. As the studies investigated very diverse screening methods, no statistical meta-analysis was performed due to methodological heterogeneity; instead, the results were synthesized narratively.

Ten studies were included, examining various alternatives such as fasting plasma glucose thresholds (sensitivity 95.6%), selective screening strategies (sensitivity 73.6%), capillary blood glucose testing (sensitivity 67.9%, 79.3%, and 92.5% for different fasting cut points), and glycated hemoglobin (HbA1c) measurements (sensitivity approximately 84%, depending on the cut-offs).

All alternatives showed inferior sensitivity compared to the standard OGTT; therefore, none can currently substitute the OGTT. However, basically all approaches have the potential to either reduce the number of OGTTs or improve access to GDM screening for more patients. Further research and validation are necessary for all approaches to safely reduce the number of OGTTs without compromising diagnostic accuracy.