What are the guidelines for diabetes management in pregnancy?

Guidelines for Diabetes Management in Pregnancy

Optimal management of diabetes in pregnancy requires strict glycemic control with specific targets for fasting and postprandial glucose levels, along with appropriate insulin therapy, nutrition counseling, and regular monitoring to reduce maternal and fetal complications. 1, 2

Preconception Care

• Target A1C <6.5% before conception to minimize risk of congenital anomalies 2
• Preconception counseling should include:
  • Medication review to discontinue potentially teratogenic drugs (ACE inhibitors, ARBs, statins) 1
  • Comprehensive eye exam, renal function assessment, and evaluation for other diabetes complications 1
  • Folic acid supplementation (400 mg daily) 1
  • Testing for rubella, syphilis, hepatitis B, HIV, and Pap smear 1
  • Counseling on risks of unplanned pregnancies with poor metabolic control 1

Glycemic Targets

For Gestational Diabetes (GDM):

• Fasting: <95 mg/dL (5.3 mmol/L)
• 1-hour postprandial: <140 mg/dL (7.8 mmol/L)
• 2-hour postprandial: <120 mg/dL (6.7 mmol/L) 1

For Preexisting Diabetes (Type 1 or Type 2):

• Premeal, bedtime, and overnight: 60–99 mg/dL (3.3–5.4 mmol/L)
• Peak postprandial: 100–129 mg/dL (5.4–7.1 mmol/L) 1

A1C Target:

• <6% if achievable without significant hypoglycemia
• May be relaxed to <7% if necessary to prevent hypoglycemia 1, 2

Monitoring Recommendations

• Both fasting and postprandial self-monitoring of blood glucose are essential 1
• Preprandial testing also recommended for women with preexisting diabetes using insulin pumps or basal-bolus therapy 1
• Postprandial monitoring is associated with better glycemic control and lower risk of preeclampsia 1, 3
• Continuous glucose monitoring (CGM) can help achieve A1C targets and reduce macrosomia and neonatal hypoglycemia 1
• A1C should be monitored more frequently (e.g., monthly) due to altered red blood cell kinetics during pregnancy 1

Insulin Therapy

• Insulin is the preferred agent for diabetes management in pregnancy due to lack of long-term safety data for non-insulin agents 1, 4
• Insulin requirements change throughout pregnancy:
  • First trimester: Often decrease in total daily dose
  • Second trimester: Rapidly increasing insulin resistance requires weekly/biweekly dose adjustments
  • Third trimester: May double compared to pre-pregnancy needs 1, 2
• Generally, a small proportion of total daily dose should be given as basal insulin and a greater proportion as prandial insulin 1
• Rapid reduction in insulin requirements in late pregnancy may indicate placental insufficiency 2

Nutrition and Lifestyle Management

• All women with diabetes in pregnancy should receive individualized nutrition counseling from a registered dietitian 2
• Carbohydrate consistency is essential to match with insulin dosage 2
• Weight gain goals based on pre-pregnancy BMI:
  • Normal weight: 25-35 lb
  • Overweight: 15-25 lb
  • Obese: 10-20 lb 1
• Regular moderate exercise is recommended if not contraindicated 2, 5

Management of GDM

• Initial management includes medical nutrition therapy, exercise, and glucose monitoring 1, 5
• If blood glucose targets cannot be maintained with lifestyle modifications, insulin therapy should be initiated 5
• 70-85% of women with GDM can control their condition with lifestyle modification alone 1

Complications and Monitoring

• Dilated eye examinations should be performed before pregnancy or in first trimester, then every trimester and for 1 year postpartum 2
• Monitor for diabetic ketoacidosis, which can occur at lower blood glucose levels during pregnancy 2
• Regular obstetric examinations including ultrasound are recommended 5
• Neonatal care of GDM offspring includes blood glucose monitoring after birth due to risk of hypoglycemia 5

Postpartum Follow-up

• All women with GDM should be reevaluated with a 75g OGTT 4-12 weeks postpartum 5
• Assessment of glucose parameters recommended every 2-3 years with normal glucose tolerance 5
• Breastfeeding should be supported in all women with diabetes 2
• Contraceptive options should be discussed to prevent unplanned pregnancy until glycemic targets are achieved 2

Key Pitfalls to Avoid

• Failing to screen high-risk women early in pregnancy (before 20 weeks) for undiagnosed type 2 diabetes 5
• Relying solely on A1C for monitoring during pregnancy instead of using both pre- and postprandial glucose values 1
• Using estimated A1C and glucose management indicator calculations during pregnancy 1
• Not adjusting insulin doses frequently enough to match changing requirements throughout pregnancy 1, 4
• Overlooking the importance of postprandial glucose monitoring, which has been shown to improve outcomes compared to preprandial monitoring alone 3