Diagnostic Criteria for Gestational Diabetes May Change Soon   (February 27, 2010)

Gestational diabetes (GDM) is the development of diabetes during pregnancy; it is associated with an increased risk of problems for both mother and baby, ranging from maternal complications such as preeclampsia to baby problems such as the increase in body size, with problems in delivering the child, and a future risk of developing diabetes for both mom and child. Treatment, with meal planning and lifestyle changes and blood glucose testing, and if needed with diabetic medications including insulin, is well-known to lessen the risk of these problems: lowering mom's blood sugar level is what is needed to lower the risks.

Currently, the ADA recommends that GDM be diagnosed based on several different (and somewhat confusing) strategies. Similar to criteria for non-pregnant adults, an FPG level >126 mg/dl (7.0 mmol/l) or a casual plasma glucose >200 mg/dl (11.1 mmol/l) is considered high enough to make the diagnosis (see Testing for gestational diabetes, at the ADA website). Or if 2 out of 3 blood glucose values are elevated on a GTT (see Diagnosis of GDM with a 100-g or 75-g glucose load) then GDM should be diagnosed.

But as the ADA points out, a 2008 study, Hyperglycemia and Adverse Pregnancy Outcomes, showed that the risk of maternal, fetal, and neonatal problems increased as the pregnant woman's glucose levels increased, "even within ranges previously considered normal for pregnancy."

According to press reports, the not-yet-available March 2010 issue of Diabetes Care will contain recommendations from a panel of experts, who will be advising that the criteria for diagnosing gestational diabetes (GDM) be revised downwards. If these recommendations are adopted, two or three times as many pregnant women might be diagnosed with and treated for GDM.

Why change the recommendations? Well, it's rather simple: if diabetic-type problems are occurring for both mother and baby at blood glucose levels below the levels presently needed to make the diagnosis of GDM, then the levels were set too high previously. Women and babies at risk rightfully ought to be identified, and subsequently treated.

Interestingly, there seems to be some hesitation to make the change in recommendations for diagnosis: one expert is quoted as saying "I worry that these [obstetrics] practices may not have the resources to suddenly double or triple their gestational diabetes caseload." But I disagree: most of these women can have their diabetes care managed by any number of heath care professionals: diabetes nurse educators, or endocrinologists, or savvy primary care physicians, or nurse practitioners or physician assistants, working together with the busy obstetricians, could care for these additional cases.

In the meantime, if you know a non-diabetic woman who has recently become pregnant, or is planning pregnancy soon, encourage her to have diabetes testing as a routine part of her prenatal care. Whether the numbers on this testing are considered high, or marginally high, or almost high, controlling her blood sugar will be advantageous for her and her child.