Abstract
This literature review assesses clinical guidelines for pre-existing diabetes and gestational diabetes mellitus (GDM) in the areas of diagnosis, management, and maternal-fetal outcomes. A structured search was conducted across PubMed and Google Scholar, supplemented by targeted screening of guideline repositories from the American Diabetes Association (ADA), National Institute for Health and Care Excellence (NICE), and World Health Organization (WHO). Included studies and guidelines were selected based on relevance to diagnosis, therapeutic strategies, or maternal-neonatal outcomes, with exclusion criteria applied to non-English publications and non-clinical recommendations. A comparative analysis of guidelines from the ADA, NICE, and WHO was performed to evaluate prevalence, therapeutic approaches, and postpartum management. Early diagnosis, stringent blood glucose control, and multidisciplinary care with the aim to avoid macrosomia, congenital abnormalities, and neonatal hypoglycemia guide the management guidelines. Glycated hemoglobin (HbA1c) (<6.5%) optimization and supplementation with folic acid are critically required prior to conception in all women with previously diagnosed diabetes. Continuous glucose monitoring (CGM) and insulin pump therapy are valued but burdened by availability and access constraints. A postpartum visit with 75 g oral glucose tolerance test (OGTT) at 4-12 weeks is essential for the detection of persistent diabetes. Variation of diagnostic criteria among guidelines reflects the requirement for standardization. Expansion of coverage by insurance for CGM and preconception care is important for providing equal access. The cost-effectiveness of new technologies and health disparities in low-resource settings must be addressed in future research.