Insulin Management in Pregnancy

Introduction to Insulin Therapy

• The American Diabetes Association recommends insulin as the preferred agent for managing diabetes in pregnancy, with a basal-bolus regimen where a small proportion of the total daily dose is given as basal insulin and a greater proportion as prandial insulin 1
• All insulins are pregnancy category B except for glargine and glulisine, which are labeled C 1
• Insulin is the preferred agent for managing type 2 diabetes mellitus during pregnancy, due to its strong safety profile for both mother and fetus, as recommended by the American Diabetes Association 2, 3, 4

Insulin Requirements and Dosage

• Insulin requirements often decrease due to enhanced insulin sensitivity, but then increase exponentially as pregnancy progresses, with a linear increase of approximately 5% per week through week 36 1, 5
• Total daily dose may decrease compared to pre-pregnancy requirements, but often doubles by the end of pregnancy 1, 5
• Weekly or biweekly increases in insulin dose are typically required, and a rapid reduction in insulin requirements can indicate placental insufficiency 1, 5
• Insulin requirements drop dramatically after delivery of the placenta, and women become very insulin sensitive immediately postpartum, requiring much less insulin than during pregnancy 4, 1, 6

Blood Glucose Monitoring and Targets

• Target blood glucose levels include:

• Fasting blood glucose targets are 70-95 mg/dL, one-hour postprandial targets are 110-140 mg/dL, and two-hour postprandial targets are 100-120 mg/dL 5
• Monitor A1C more frequently (e.g., monthly) due to altered red blood cell kinetics during pregnancy, and pre- and postprandial monitoring is recommended 1, 5

Insulin Administration and Safety

• Abdomen is generally a safe site for insulin administration, and 4-mm pen needles are recommended due to thinning of abdominal fat from uterine expansion 7
• Increased risk of hypoglycemia in first trimester, and altered counter-regulatory response may decrease hypoglycemia awareness, emphasizing the need for patient and family education on prevention, recognition, and treatment 6, 2, 4
• Education for patients and family members about prevention, recognition, and treatment of hypoglycemia is essential, as recommended by the American Diabetes Association 2, 4

Additional Recommendations

• Prescribe low-dose aspirin 100-150 mg/day starting at 12-16 weeks gestation to reduce preeclampsia risk, as recommended by the American College of Obstetricians and Gynecologists and the American Diabetes Association 2, 6, 3, 4
• Medical nutrition therapy with an individualized meal plan developed by a registered dietitian is recommended, and weight gain recommendations include 15-25 lbs for overweight women and 10-20 lbs for obese women, as suggested by the American Diabetes Association 4
• Lifestyle changes are the first-line approach for gestational diabetes, as recommended by the American College of Obstetricians and Gynecologists 8
• Postpartum screening for persistent diabetes or prediabetes with a 75-g OGTT at 4-12 weeks is recommended, according to the American Diabetes Association 4
• Implementing a contraceptive plan for all women with diabetes of reproductive potential is essential, as suggested by the American Diabetes Association 9
• Women with Type 1 diabetes should aim for a target A1C of <6.5% (48 mmol/mol) before conception to minimize the risk of congenital anomalies, as recommended by the American Diabetes Association 9, 8
• Effective contraception should be used until the woman is ready for pregnancy, and medication review for potentially teratogenic drugs (ACE inhibitors, ARBs, statins) should be performed 9, 4, 8
• A comprehensive eye exam to assess retinopathy status should be done before conception, and regular eye exams are recommended each trimester, as retinopathy may worsen during pregnancy, especially with rapid improvement in glycemic control 9, 8