Management of Gestational Diabetes Mellitus

Introduction to GDM Management

• The American Diabetes Association recommends that lifestyle modification is the cornerstone of GDM management and is sufficient for 70-85% of women, with insulin being the preferred pharmacological therapy when needed to achieve glycemic targets 1
• GDM is characterized by increased risk of large-for-gestational-age birth weight, neonatal complications, and long-term risk of maternal type 2 diabetes and abnormal glucose metabolism in offspring 1

Diagnosis and Clinical Features

• Risks increase progressively with maternal hyperglycemia, with no clear inflection points 1
• Offspring exposed to untreated GDM have reduced insulin sensitivity, impaired β-cell compensation, and higher likelihood of impaired glucose tolerance in childhood 1

Treatment Goals

• The recommended glycemic targets for GDM management are: fasting glucose <95 mg/dL, one-hour postprandial glucose <140 mg/dL, and two-hour postprandial glucose <120 mg/dL 1, 2

First-Line Management: Lifestyle Modifications

• Medical Nutrition Therapy (MNT) should be individualized and developed with a registered dietitian familiar with GDM management, providing adequate calories to promote fetal/neonatal and maternal health, achieve glycemic targets, and support appropriate gestational weight gain 1, 3
• Dietary recommendations include: minimum 175g of carbohydrate daily, minimum 71g of protein daily, and 28g of fiber daily 2, 3
• Emphasis on monounsaturated and polyunsaturated fats while limiting saturated fats and avoiding trans fats 2

Second-Line Management: Pharmacological Therapy

• Insulin is the preferred medication for treating hyperglycemia in GDM as it does not cross the placenta to a measurable extent 1, 2, 3
• Metformin and glyburide should not be used as first-line agents as both cross the placenta 1, 3
• Glyburide has minimal placental transfer but has been associated with increased neonatal hypoglycemia and macrosomia compared to insulin 3, 4

Monitoring and Follow-up

• Self-monitoring of blood glucose is essential to assess glycemic control 2
• Telehealth visits for GDM patients improve outcomes compared with standard in-person care 1
• Women with GDM have increased risk of hypertensive disorders during pregnancy; blood pressure and urinary protein should be monitored at each prenatal visit 4

Common Pitfalls and Caveats

• Failure to recognize that 70-85% of women can manage GDM with lifestyle modification alone, potentially leading to unnecessary medication use 1, 3
• Assuming oral antihyperglycemic agents are equivalent to insulin in safety and efficacy 1, 3