From the Guidelines
Metformin should not be used as a first-line agent for treating gestational diabetes mellitus (GDM), and insulin is the preferred medication. According to the standards of care in diabetes-2023 1, metformin and glyburide should not be used as first-line agents for GDM as both cross the placenta to the fetus.
Key Points to Consider
- The management of GDM involves lifestyle behavior change, which may suffice as treatment for many individuals, and insulin should be added if needed to achieve glycemic targets 1.
- Metformin, when used to treat polycystic ovary syndrome and induce ovulation, should be discontinued by the end of the first trimester 1.
- There is no clear recommendation for the use of metformin ER or IR for GDM, but it is essential to note that metformin treatment in pregnancy does not reduce the risk of GDM in high-risk individuals with obesity, polycystic ovary syndrome, or preexisting insulin resistance 1.
Clinical Considerations
- GDM is characterized by an increased risk of large-for-gestational-age birth weight and neonatal and pregnancy complications, and an increased risk of long-term maternal type 2 diabetes and abnormal glucose metabolism of offspring in childhood 1.
- Telehealth visits for pregnant people with GDM improve outcomes compared with standard in-person care 1.
- The risk of GDM may be reduced by diet, exercise, and lifestyle counseling, particularly when interventions are started during the first or early in the second trimester 1.
From the Research
Metformin Formulations for GDM
- Metformin is available in two main formulations: extended-release (ER) and immediate-release (IR) [(2,3,4,5,6)].
- The choice between ER and IR metformin for gestational diabetes mellitus (GDM) depends on various factors, including patient preference, side effect profile, and glycemic control goals.
Efficacy and Safety of Metformin in GDM
- Studies have shown that metformin is effective in reducing gestational weight gain, neonatal hypoglycemia, and macrosomia in women with GDM [(2,4,5)].
- Metformin has also been found to increase insulin sensitivity and reduce the risk of gestational hypertension complications in GDM patients [(2,4)].
- However, some studies have raised concerns about the safety of metformin in pregnancy, including the potential for increased risk of preterm birth and preeclampsia 3.
Comparison of Metformin with Insulin in GDM
- Metformin has been compared with insulin in several studies, with mixed results [(2,3,5)].
- Some studies have found that metformin is as effective as insulin in achieving glycemic control in women with GDM [(2,5)].
- However, other studies have raised concerns about the safety and efficacy of metformin compared with insulin 3.
Specific Formulation (ER or IR) Used in GDM
- The provided studies do not specifically mention whether the extended-release (ER) or immediate-release (IR) formulation of metformin is used for GDM [(2,3,4,5,6)].
- Further research is needed to determine the optimal formulation of metformin for use in GDM.