Objective: The present study’s purpose is to evaluate the economic context in which the Brazilian public health system, the only universal public health system with more than 200 million users, stands out. This evaluation will be made through the lens of the execution of gestational health care services in a city of approximately 500 thousand inhabitants in southern Brazil. The care costs of patients with gestational diabetes mellitus (GDM) will be compared to those of patients without GDM, analyzing the different economic valuation methods. And lastly, there was an intent to explore the generated costs in the context of economic valuation applied to health to comprehend better the complexity of the union of the financial and health areas to optimize the services offered. Methods: For the economic context in health, an analysis of health investments was performed through the Transparency Portal. The costs involved in preventing GDM were raised by the Sistema Único de Saúde (SUS) table of procedures performed ordinarily in low-risk pregnancies. The expenses involved in DMG patients were increased at the High-Risk Pregnancy and Fetal Medicine Clinic of DMG patients. Results: Preventing GDM is more cost-effective, cost-minimizing, and cost-useful than treating patients diagnosed with GDM. Conclusion: The result is an extremely interesting costopportunity, given the economic context in which it is presented