Can insulin glargine (glargine insulin) be used in pregnancy for gestational diabetes mellitus (GDM)?

From the Guidelines

Insulin glargine can be used in pregnancy for gestational diabetes mellitus (GDM) when insulin therapy is needed, as it is considered safe and effective based on recent clinical guidelines. According to the 2023 standards of care in diabetes 1, insulin is the preferred medication for treating hyperglycemia in GDM, and lifestyle behavior change is an essential component of management. The guidelines recommend adding insulin if needed to achieve glycemic targets, and insulin glargine is a suitable option.

When considering the use of insulin glargine in pregnancy, it is essential to note that the goal is to maintain fasting glucose below 95 mg/dL (5.3 mmol/L) 1. Typical initial dosing is 0.2 units/kg body weight given once daily, usually at bedtime, with subsequent dose adjustments based on fasting blood glucose levels. Patients should monitor blood glucose regularly and may need additional rapid-acting insulin with meals if post-meal glucose levels remain elevated.

Key points to consider when using insulin glargine in pregnancy for GDM include:

• Insulin glargine provides a steady, long-acting basal insulin coverage for approximately 24 hours with minimal peak effect, which helps control fasting hyperglycemia 1
• The safety profile of insulin glargine in pregnancy is reassuring because the large molecule size limits placental transfer, minimizing fetal exposure, and it does not cause hypoglycemia more frequently than other insulin types when properly dosed 1
• Telehealth visits for pregnant people with GDM can improve outcomes compared with standard in-person care, including reduction of incidences of cesarean delivery, neonatal hypoglycemia, and other complications 1

From the FDA Drug Label

Published studies with use of insulin glargine during pregnancy have not reported a clear association with insulin glargine and adverse developmental outcomes There are risks to the mother and fetus associated with poorly controlled diabetes in pregnancy Published data do not report a clear association with insulin glargine and major birth defects, miscarriage, or adverse maternal or fetal outcomes when insulin glargine is used during pregnancy

Insulin glargine can be used in pregnancy for gestational diabetes mellitus (GDM), as there is no clear association with adverse developmental outcomes. However, caution is advised due to the risks associated with poorly controlled diabetes in pregnancy.

• Key considerations:
  • Risks to the mother and fetus associated with poorly controlled diabetes in pregnancy
  • No clear association with insulin glargine and adverse developmental outcomes
  • Published data may have methodological limitations, including small sample size and lacking comparator groups 2, 2, 2

From the Research

Insulin Glargine Use in Pregnancy for GDM

• Insulin glargine can be used in pregnancy for gestational diabetes mellitus (GDM), as there are no major safety concerns reported in studies 3, 4, 5, 6.
• Most studies on insulin glargine use in pregnancy are small and retrospective, but they suggest that it is a viable option for achieving excellent glycemic control 3, 5.
• A systematic review and meta-analysis found no statistically significant differences in fetal outcomes between insulin glargine and NPH insulin use in pregnancy 4.
• Insulin glargine may be continued if required to achieve excellent glycemic control, especially in women with pre-existing diabetes or GDM 5.
• However, the use of insulin glargine in pregnancy is not without controversy, and some studies suggest that it may not be necessary for women with well-controlled diabetes on human insulin or NPH insulin 7, 5.

Key Findings

• No increased risk of adverse fetal outcomes was found with insulin glargine use compared to NPH insulin 4.
• Insulin glargine may improve glycemic control in women with type 1 diabetes, but the evidence for improved fetal outcomes is limited 5, 6.
• The use of insulin glargine in women with GDM or type 2 diabetes may not be justified due to the low risk of hypoglycemia 5.

Study Limitations

• Most studies on insulin glargine use in pregnancy are small and retrospective, which may limit the generalizability of the findings 3, 5, 6.
• More research is needed to fully understand the safety and efficacy of insulin glargine use in pregnancy, especially in women with GDM or type 2 diabetes 3, 7, 5.