What insulin is recommended in pregnancy for Gestational Diabetes Mellitus (GDM)?

From the FDA Drug Label

Published studies with insulin lispro used during pregnancy have not reported an association between insulin lispro and the induction of major birth defects, miscarriage, or adverse maternal or fetal outcomes Available information from published randomized controlled trials with insulin aspart use during the second trimester of pregnancy have not reported an association with insulin aspart and major birth defects or adverse maternal or fetal outcomes

Insulin Recommended in Pregnancy for GDM:

• Insulin Lispro: can be used during pregnancy, as studies have not reported an association with major birth defects, miscarriage, or adverse maternal or fetal outcomes 1
• Insulin Aspart: can be used during pregnancy, as studies have not reported an association with major birth defects or adverse maternal or fetal outcomes 2 Key Considerations:
• Poorly controlled diabetes in pregnancy increases the maternal risk for diabetic ketoacidosis, pre-eclampsia, spontaneous abortions, preterm delivery, and delivery complications
• Poorly controlled diabetes increases the fetal risk for major birth defects, stillbirth, and macrosomia related morbidity Recommendation:
• Insulin lispro and insulin aspart can be considered for use in pregnancy for GDM, as they have not been associated with major birth defects or adverse maternal or fetal outcomes. However, it is essential to carefully monitor blood glucose levels and adjust the insulin dose as needed to maintain good glycemic control.

From the Research

Insulin is the recommended treatment for gestational diabetes mellitus (GDM) when dietary and lifestyle modifications fail to achieve target blood glucose levels. According to the most recent study 3, fasting glucose level is the main determinant of insulin use in patients with GDM. The study found that 56.7% of women with GDM required insulin treatment, and that fasting glucose, pre-conceptional body mass index (BMI), parity, and third-trimester glycated hemoglobin levels were all higher in the insulin-treated group.

Key Recommendations

• Target glucose levels are typically fasting <95 mg/dL and 2-hour postprandial <120 mg/dL 4
• Short- and intermediate-acting human insulin are the first choice of insulin regimens, with rapid-acting insulin (such as insulin aspart or lispro) considered for postprandial hyperglycemia 4
• Basal/intermediate-acting insulin should be used at bedtime if fasting plasma glucose (FPG) is greater than 110 mg/dL 4
• During intrapartum, IV insulin infusion with hourly glucose monitoring should be started, and those women who require insulin < 20 U over 24 hours prior to labor may not need intrapartum use of insulin infusion 4
• Insulin dosing should be stopped after birth, and capillary glucose monitoring should be performed for 24-48 hours 4

Insulin Regimens

• A typical starting regimen might include intermediate-acting NPH insulin at bedtime (starting at 0.2 units/kg) for fasting hyperglycemia, or rapid-acting insulin before meals (starting at 1-2 units per 10g carbohydrates) for postprandial hyperglycemia
• Insulin requirements often increase throughout pregnancy, particularly in the second and third trimesters, requiring dose adjustments based on blood glucose monitoring

Patient Education

• Patients should be taught proper insulin administration techniques, hypoglycemia recognition and management, and the importance of consistent carbohydrate intake and regular blood glucose monitoring
• The choice to use insulin or oral anti-diabetic pharmacological therapies may be down to physician or maternal preference, availability, or severity of GDM 5