Objectives: We focused on four questions:
- What are the risks and benefits of an oral diabetes agent (i.e., glyburide), as compared to all types of insulin, for gestational diabetes?
- What is the evidence that elective labor induction, cesarean delivery, or timing of induction is associated with benefits or harm to the mother and neonate?
- What risk factors are associated with the development of type 2 diabetes after gestational diabetes?
- What are the performance characteristics of diagnostic tests for type 2 diabetes in women with gestational diabetes?
Data Sources: We searched electronic databases for studies published through January 2007. Additional articles were identified by searching the table of contents of 13 journals for relevant citations from August 2006 to January 2007 and reviewing the references in eligible articles and selected review articles.
Review Methods: Paired investigators reviewed abstracts and full articles. We included studies that were written in English, reported on human subjects, contained original data, and evaluated women with appropriately diagnosed gestational diabetes. Paired reviewers performed serial abstraction of data from each eligible study. Study quality was assessed independently by each reviewer.
Main Results: The search identified 45 relevant articles. The evidence indicated that:
- Maternal glucose levels do not differ substantially in those treated with insulin versus insulin analogues or oral agents.
- Average infant birth weight may be lower in mothers treated with insulin than with glyburide.
- Induction at 38 weeks may reduce the macrosomia rate, with no increase in cesarean delivery rates.
- Anthropometric measures, fasting blood glucose (FBG), and 2-hour glucose value are the strongest risk factors associated with development of type 2 diabetes.
- FBG had high specificity, but variable sensitivity, when compared to the 75-gm oral glucose tolerance test (OGTT) in the diagnosis of type 2 diabetes after delivery.
Conclusions: The evidence suggests that benefits and a low likelihood of harm are associated with the treatment of gestational diabetes with an oral diabetes agent or insulin. The effect of induction or elective cesarean on outcomes is unclear. The evidence is consistent that anthropometry identifies women at risk of developing subsequent type 2 diabetes; however, no evidence suggested the FBG out-performs the 75-gm OGTT in diagnosing type 2 diabetes after delivery.
Therapeutic Management, Delivery, and Postpartum Risk Assessment and Screening in Gestational Diabetes
Evidence-based Practice Center: Johns Hopkins University
Topic Nominator: American College of Obstetricians and Gynecologists (ACOG)