Gestational diabetes

We have developed a special registry for gestational diabetes mellitus (GDM) which allows us to accurately identify and exclude true GDM patients who are misclassified as diabetes. Furthermore, this large GDM registry facilitates GDM epidemiology and health services research. GDM is defined by hyperglycemia and/or physician diagnosis. We found that many GDM cases were missed if the criteria was based on either a GDM diagnosis alone or a laboratory measure during pregnancy alone -- during the period 1991-1999, approximately 30% of the GDM cases had a physician diagnosis and normoglycemia and 20% had hyperglycemia but no physician diagnosis. Additionally some pregnant women with concurrent hyperglycemia received an outpatient diagnosis of diabetes mellitus, although they appear to be GDM since they had the screening test (patients with previously diagnosed diabetes should not have had the screening test). Given these complexities, we found it useful to create a GDM registry with eligibility criteria and validation studies, and use it to help identify patients misclassified as having diabetes mellitus.