Introduction <p>Gestational Diabetes Mellitus is one of the most common metabolic complications of pregnancy, affecting approximately 15.6% of pregnancies worldwide. Women diagnosed with gestational diabetes face a significantly elevated risk of developing type 2 diabetes mellitus later in life. Despite the availability of systematic reviews exploring individual risk factors, there is a lack of consolidated evidence that provides a global perspective on the determinants of type 2 diabetes mellitus progression following gestational diabetes. Therefore, we aimed to systematically synthesize findings from existing systematic reviews and meta-analyses.</p> Methods <p>A comprehensive literature search was conducted across several databases, including PubMed, EMBASE, ScienceDirect, Cochrane library and google scholar, using the PECO (Population, Exposure, Comparator, Outcome) framework. Systematic reviews and meta-analyses published between January 1, 2005, and January 1, 2025, were included. Data were extracted by two reviewers independently and a structured synthesis was conducted due to heterogeneity in reported effect measures.</p> Result <p>Twelve systematic reviews and meta-analyses comprising over 400 primary studies and more than 6 million participants were included. The most consistently reported risk factors for progression from gestational diabetes mellitus to type 2 diabetes mellitus included insulin use during pregnancy, elevated body mass index before or after pregnancy, and a positive family history of diabetes. Glycemic markers such as fasting blood glucose, oral glucose tolerance test values, and glycated hemoglobin were also frequently associated with increased risk. Additional risk factors included advanced maternal age, non-white ethnicity, hypertension, and recurrent gestational diabetes. In contrast, lactation was consistently associated with a reduced risk of type 2 diabetes mellitus.</p> Conclusion <p>This umbrella review offers a comprehensive understanding of the complex factors that influence the transition from gestational diabetes to type 2 diabetes. It brings together diverse findings to highlight how clinical indicators, lifestyle factors, and social determinants interact to shape long-term health outcomes. Notably, while certain risk factors such as insulin use, elevated BMI, family history of diabetes, abnormal glycemic markers, advanced maternal age, non-white ethnicity, hypertension, and recurrent consistently increase vulnerability, lactation stands out as a protective behavior. These insights reinforce the importance of individualized postpartum care and proactive risk management to support women’s health beyond pregnancy.</p>