Using oral hypoglycemics in pregnancy to manage type 2 gestational diabetes.
Oral hypoglycemic are commonly used to treat type 2 diabetes in non pregnant adults, but data are limited on the safety and efficacy for treatment of pre-existing diabetes in pregnancy. Glyburide is an acceptable alternative to insulin for treatment of gestational diabetes that does not respond to diet and insulin.
Epidemiology/Incidence: Although commonly used in non pregnant adults, data on use of oral hypoglycemic to treat pre-existing diabetes in pregnancy are limited.
- Glyburide directly stimulates insulin release from the pancreas and is transferred in low-levels across the placenta.
- Metformin enhances insulin sensitivity in the liver and peripheral tissues and is readily transferred across the placenta.
- Given the limited data on safety, especially in the first trimester, women on oral agents should be switched to insulin therapy.
- Since gestational diabetes is due to inadequate maternal response to increased insulin resistance occurring typically after 20 weeks’ gestation, oral hypoglycemics may be an acceptable alternative to insulin.
- Compared to insulin, glyburide does not appear to be associated with an increase in neonatal complications and only 4% of women in a clinical trial required conversion to insulin.
- Glyburide is started at 2.5 mg once or twice a day and may be increased to a daily maximum of 20 mg.
- Compared to insulin, metformin does not appear to be associated with an increase in perinatal complications, but 46% of women in a clinical trial required conversion to insulin.
- Metformin is started at 500 mg once or twice daily and increased to a daily maximum of 2,500 mg.
- Attainment of euglycemia is the goal of therapy regardless of the therapy utilized and the targets are the same whether insulin or oral agents are used.
Post-partum/breastfeeding: Exposure of infants to oral hypoglycemic agents through breastmilk is minimal; mothers on these agents should be encouraged to breastfeed.