What is the management plan for borderline gestational diabetes (GDM)?

Management of Borderline Gestational Diabetes

Lifestyle modifications are the cornerstone of management for borderline gestational diabetes and may suffice as treatment for 70-85% of women diagnosed with GDM. 1, 2

Initial Management Approach

• Begin with medical nutrition therapy, physical activity, and weight management while monitoring blood glucose levels targeting the following glycemic goals 1, 2:

  • Fasting glucose <95 mg/dL (5.3 mmol/L)
  • One-hour postprandial glucose <140 mg/dL (7.8 mmol/L) or
  • Two-hour postprandial glucose <120 mg/dL (6.7 mmol/L)

• Self-monitoring of blood glucose is essential to assess glycemic control and determine if lifestyle modifications are sufficient 3

Medical Nutrition Therapy

• An individualized nutrition plan should be developed with a registered dietitian nutritionist (RDN) familiar with GDM management 1

• The nutrition plan should include 1, 3:

  • Minimum of 175g of carbohydrates (35% of a 2,000-calorie diet)
  • Minimum of 71g of protein
  • 28g of fiber
  • Emphasis on monounsaturated and polyunsaturated fats
  • Limited saturated fats and no trans fats

• Focus on controlling the amount and type of carbohydrates to manage postprandial glucose excursions 4

• Simple carbohydrates should be limited as they result in higher postmeal glucose excursions 1

Physical Activity

• Regular physical activity improves glucose outcomes and may reduce the need for insulin 1

• Recommend 150 minutes of moderate-intensity aerobic activity per week, preferably distributed throughout the week 3

• Both aerobic and resistance exercise have shown benefits, with effective interventions ranging from 20-50 minutes per day, 2-7 days per week 1

Monitoring Protocol

• Regular blood glucose monitoring is essential to evaluate the effectiveness of lifestyle interventions 3

• Postprandial monitoring is particularly important as it's associated with better glycemic control and lower risk of preeclampsia 3

• Consider ultrasound measurements of fetal abdominal circumference starting in the second and early third trimesters to guide management decisions 2

When to Escalate Treatment

• Add pharmacological therapy when lifestyle modifications fail to achieve glycemic targets 1

• Insulin is the preferred medication for treating hyperglycemia in GDM as it does not cross the placenta to a measurable extent 1

• Metformin and glyburide should not be used as first-line agents as both cross the placenta and lack long-term safety data for offspring 1

Postpartum Follow-up

• All women with GDM should be tested for persistent diabetes or prediabetes at 4-12 weeks postpartum with a 75-g OGTT 2, 3

• Continue testing every 1-3 years due to the 50-70% lifetime risk of developing type 2 diabetes 2

• Encourage breastfeeding and postpartum weight loss for women who were overweight or obese during pregnancy 2, 5

Common Pitfalls to Avoid

• Failing to recognize that even borderline GDM increases risks for adverse maternal and fetal outcomes 2, 6

• Inadequate monitoring of blood glucose levels or assuming lifestyle modifications are sufficient without proper verification 2

• Overlooking the importance of postpartum testing for diabetes and long-term follow-up 2, 5

• Not providing adequate education about the increased risk of developing type 2 diabetes later in life 2, 6