Three types of diabetes may complicate pregnancy: preexisting type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), or gestational diabetes mellitus (GDM). By definition, the first two types of diabetes are already established prior to pregnancy. GDM, also referred to as hyperglycemia in pregnancy, is a condition in which glucose intolerance develops in a patient who has not been previously diagnosed with diabetes.1,2
GDM is typically a milder form of diabetes than either T1DM or T2DM and is likely to require less intensive treatment than preexisting disease. Whereas T1DM and T2DM persist beyond pregnancy, glucose tolerance typically returns to normal postpartum in women with GDM.1 However, women with a history of GDM do have an increased risk of developing T2DM over the long term.3
Based on 1995 data reported by the US Centers for Disease Control (CDC), it has been estimated that 88% of US pregnancies complicated by diabetes mellitus involve GDM, 8% involve T2DM, and 4% involve T1DM.4 A more recent study estimates that, between 1980 and 2008, the rate of diabetes during pregnancy (both GDM and preexisting) has increased from 5.0% to 8.7% among white women, and from 5.7% to 9.7% among African American women.5 Since the reported incidence of T2DM in younger patients has increased dramatically since the 1990s, it is likely that the percentage of pregnancies complicated by preexisting diabetes has increased substantially.6,7
Due to higher rates of obesity and increasingly sedentary lifestyles in the United States, the prevalence of both GDM and T2DM are growing.1 Currently, GDM is reported to occur in 2% to 10% of pregnancies. However, recent updates to GDM diagnostic criteria are expected to increase the number of women diagnosed with this condition. Under the new criteria, it is estimated that 18% of pregnancies will be complicated by GDM.3,8,9
Morbidity and Mortality
Prior to the availability of modern diagnostic and treatment options such as insulin therapy, pregnancies complicated by diabetes were associated with a >90% infant mortality rate and a 30% maternal mortality rate.10 The development of more sophisticated diabetes screening and diagnostic tools, combined with more effective approaches to monitor and manage glucose levels, have provided the means to substantially improve glycemic control during pregnancy. These advances have made it possible to dramatically reduce morbidity and mortality in both mothers and infants.10,11
GDM is associated with an increased risk of complications in both pregnant women and their offspring. Women with GDM have a greater likelihood of preeclampsia, caesarean delivery, and subsequent development of T2DM. Fetal and neonatal GDM risks include birth injuries, childhood obesity, hyperbilirubinemia, hypoglycemia, macrosomia, shoulder dystocia, and respiratory distress syndrome.12
Cost-Effectiveness of Treating Diabetes in Pregnancy
Treatment of diabetes in pregnancy may not only improve outcomes for female patients and their children but may also represent a cost-effective long-term strategy for reducing the prevalence of obesity, T2DM, and metabolic syndrome.13
A recent cost-effectiveness analysis modeled the cost-utility of proposed updates to GDM screening and diagnostic criteria versus current GDM screening practices or no screening at all.14 The new approach, which was proposed by the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) and is supported by the American Association of Clinical Endocrinologists (AACE) and the American Diabetes Association (ADA), was shown to be cost-effective when post-delivery intervention led to a decreased incidence of future T2DM in GDM patients.14
According to the analysis, for every 100,000 women screened under the updated criteria, 6178 quality-adjusted life-years (QALY) are gained at a total cost of almost $126 million.14 Compared with current GDM screening practices, the new IADPSG strategy has an incremental cost-effectiveness ratio (ICER) of $20,336 per QALY gained.14
In the next section, screening for GDM will be discussed in detail, including etiology, risk factors, etiology of GDM, specific screening recommendations, and diagnosis.
- Chitayat L, Zisser H, Jovanovic L. Continuous glucose monitoring during pregnancy. Diabetes Technol Ther. 2009;11(Suppl 1):S105-111.
- Handelsman Y, Mechanick JI, Blonde L, et al. American Association of Clinical Endocrinologists. Medical guidelines for clinical practice for developing a diabetes mellitus comprehensive care plan. Endocr Pract. 2011;17(Suppl 2):1-53.
- Centers for Disease Control and Prevention. 2011 National Diabetes Fact Sheet. 2011; Available at: http://www.cdc.gov/diabetes/pubs/estimates11.htm#10.
- Engelgau MM, Herman WH, Smith PJ, German RR, Aubert RE. The epidemiology of diabetes and pregnancy in the U.S., 1988. Diabetes Care. 1995;18:1029-1033.
- Hunt KJ, Reifsnider OS, Mayorga ME. Prevalence Estimates of Diabetes During Pregnancy in United States Women, 1980 to 2008. Obesity 2012 30th Annual Scientific Meeting. San Antonio, Texas. 2012.
- Pinhas-Hamiel O, Zeitler P. Clinical presentation and treatment of type 2 diabetes in children. Pediatr Diabetes. 2007;8(Suppl 9):16-27.
- National Diabetes Education Program. Overview of diabetes in children and adolescents. 2011; Available at: http://ndep.nih.gov/media/Youth_FactSheet.pdf.
- American Diabetes Association. Standards of medical care in diabetes–2013. Diabetes Care. 2013;36(Suppl 1):S11-S66.
- American Diabetes Association. What is gestational diabetes? 2012; Available at: http://www.diabetes.org/diabetes-basics/gestational/what-is-gestational-diabetes.html.
- Jovanovic L. Insulin therapy in pregnancy. In: Leahy J, Cefalu W, editors. Insulin Therapy. New York: Marcel Dekker Inc; 2002. p. 139-151.>
- Jovanovic L, Peterson CM. Optimal insulin delivery for the pregnant diabetic patient. Diabetes Care. 1982;5(Suppl 1):24-37.
- The American College of Obstetricians and Gynecologists. Committee opinion no. 504: Screening and diagnosis of gestational diabetes mellitus. Obstet Gynecol. 2011;118:751-753.
- Castorino K, Jovanovic L. Pregnancy and diabetes management: advances and controversies. Clin Chem. 2011;57:221-230.
- Werner EF, Pettker CM, Zuckerwise L, et al. Screening for gestational diabetes mellitus: are the criteria proposed by the international association of the Diabetes and Pregnancy Study Groups cost-effective? Diabetes Care. 2012;35:529-535.