Gestational Diabetes Mellitus and Obesity

Abstract

This is the sixth of a series of articles based on presentations at the American Diabetes Association (ADA) Scientific Sessions held 5–9 June 2009 in New Orleans, Louisiana. ### Gestational diabetes mellitus In a symposium on advances in the understanding of obesity and weight gain during pregnancy, Teresa A. Hillier (Portland, OR) discussed the implications that pregnancy weight gain in gestational diabetes mellitus (GDM) has for the fetus. Much of the discussion following her lecture and those of the other speakers concerned the May 2009 guidelines of the Institute of Medicine (IOM) for weight gain during pregnancy (www.iom.edu/pregnancyweightgain), which suggest that recommendations to patients be based on prepregnancy BMI. For BMI levels 30 kg/m2, weight gain ranges are suggested at 28–40, 25–35, 15–25, and 11–20 pounds, respectively, and the recommended rates of weight gain are 1–1.3, 0.8–1, 0.5–0.7, and 0.4–0.6 pounds/week. GDM is defined as any degree of glucose intolerance with onset or first recognition during pregnancy. Hillier noted the lack of consensus on screening and diagnostic criteria for GDM. In the U.S. two steps are used, a 1-h 50-g glucose challenge followed by a 75- or 100-g oral glucose tolerance test (OGTT); outside the U.S., a 2-h 75-g OGTT is recommended. The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study of providers blinded to GDM status reported correlations between fasting, 1-h, and 2-h glucose levels and adverse outcomes, including Caesarian section (1). The Australian Carbohydrate Intolerance Study in Pregnant Women (ACHOIS) was a randomized controlled trial of 1,000 women with normal fasting glucose not having GDM by World Health Organization criteria (2-h glucose 140–199 mg/dl) assigned to treatment with dietary advice, self-monitoring, and insulin as required or to routine care (2). There was gestational weight gain of 8.1 vs. 9.8 kg, and adverse fetal outcomes occurred in 7 …