What are the management and prevention strategies for complications of Gestational Diabetes Mellitus (GDM)?

Management and Prevention Strategies for Complications of Gestational Diabetes Mellitus (GDM)

Lifestyle modifications are the cornerstone of GDM management and may be sufficient for many patients, with insulin added only when needed to achieve glycemic targets. 1

Initial Management Approach

Lifestyle and Behavioral Management

• Treatment begins with medical nutrition therapy, physical activity, and weight management, with glucose monitoring targeting the following values 1:
  • 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)

Medical Nutrition Therapy (MNT)

• An individualized nutrition plan should be developed with a registered dietitian nutritionist (RDN) familiar with GDM management 1
• The food plan should provide adequate calorie intake to promote fetal/neonatal and maternal health, achieve glycemic goals, and promote appropriate weight gain 1
• For overweight and obese women, modest energy and carbohydrate restriction may be appropriate, but ketone monitoring is recommended to avoid starvation ketosis 1
• Adjusting the amount and type of carbohydrates is crucial to achieve target postprandial glucose levels 1, 2
• Training patients in carbohydrate counting, food records, and postprandial glucose testing is recommended 1

Physical Activity

• Regular physical activity has beneficial effects on glucose and insulin levels, contributing to better glycemic control 2
• Exercise should be incorporated into the management plan unless contraindicated 1

Pharmacological Management

Insulin Therapy

• Insulin is the preferred medication for treating hyperglycemia in GDM when lifestyle modifications are insufficient 1
• No specific insulin or insulin analog regimen has demonstrated superiority in GDM; administration should be individualized 1
• Insulin should be added when glycemic targets are not met or when excessive fetal growth is detected despite good glycemic control 1

Oral Antihyperglycemic Agents

• Metformin and glyburide should not be used as first-line agents as both cross the placenta to the fetus 1
• Glyburide has minimal placental transfer (4% ex vivo) and can be considered as an adjunct to lifestyle modifications when insulin is not an option 1
• Metformin used to treat polycystic ovary syndrome should be discontinued by the end of the first trimester 1
• Other oral and non-insulin injectable glucose-lowering medications lack long-term safety data 1

Monitoring and Surveillance

Maternal Monitoring

• Self-monitoring of blood glucose (SMBG) is essential for assessing glycemic control 1
• Continuous glucose monitoring (CGM) may be beneficial for patients with type 1 diabetes but is not established for GDM 1
• Telehealth visits have been shown to improve outcomes compared with standard in-person care 1
• Psychosocial assessment is encouraged to detect issues such as depression, eating disorders, stress, and anxiety that may interfere with treatment adherence 1

Fetal Surveillance

• Ultrasound measurement of fetal abdominal circumference starting in the second and early third trimesters, repeated every 2-4 weeks, can guide management decisions 1
• Lower glycemic targets or intensified therapy may be needed if fetal abdominal circumference exceeds the 75th percentile 1
• Mothers should be taught to monitor fetal movements during the last 8-10 weeks of pregnancy 1

Prevention of Long-term Complications

Postpartum Care

• Women with GDM should be tested for persistent diabetes or prediabetes at 4-12 weeks postpartum with a 75-g OGTT using non-pregnancy criteria 1
• Continued testing every 1-3 years is recommended, as GDM is associated with a 50-70% lifetime risk of developing type 2 diabetes 1
• Breastfeeding is recommended as it may reduce obesity in children and provide metabolic benefits to both mother and offspring 1, 3

Lifestyle Interventions for Prevention

• Postpartum weight loss should be encouraged for women who were overweight or obese during pregnancy 1
• Healthy eating patterns have been associated with significantly lower subsequent diabetes risk after GDM 1
• Both metformin and intensive lifestyle intervention can prevent or delay progression to diabetes in women with prediabetes and a history of GDM 1

Special Considerations

Timing of Delivery

• Women with diet-controlled GDM can wait for spontaneous labor if there are no obstetric indications for earlier birth 4
• For women with GDM under insulin therapy or with poor glycemic control, elective induction at term is generally recommended 4
• Delivery during the 39th week of gestation may provide the best balance of maternal and fetal outcomes 5

Family Planning

• All women with a history of GDM should have family planning options reviewed regularly 1
• Planning pregnancy is critical due to the increased risk of recurrent GDM in subsequent pregnancies 1

Common Pitfalls and Caveats

• Failure to recognize the continuous relationship between maternal hyperglycemia and adverse outcomes - there are no clear inflection points 1
• Inadequate monitoring of fetal growth, which is crucial for guiding management decisions 1
• Overlooking the importance of postpartum testing for diabetes, as many women with GDM have undiagnosed type 2 diabetes 1
• Neglecting the long-term follow-up needed for women with a history of GDM due to their high risk of developing type 2 diabetes 1
• Insufficient attention to carbohydrate quality and distribution throughout the day, which significantly impacts postprandial glucose excursions 2

By implementing these comprehensive management and prevention strategies, the risk of both short-term and long-term complications of GDM can be significantly reduced for both mother and child.